For games purchased from Impulse, you only need to open the client for installation and updates. If you so choose, you can never update your games, which means you would only need to run Impulse for downloading and installation.
Think of Impulse as a more robust GOG Downloader (the Adobe AIR app), or a hybrid of Steam and the GOG Downloader.
As for some of your other concerns, I can't speak for Stardock on some of the technical details. I encourage you to visit the Impulse forums (impulsedriven.com) and ask the Stardock devs. Better yet, you can find them in #stardock on irc.stardock.com, usually during work hours (9-5 CST). Zoomba, Yarlen, and Shirley are members of the Impulse team who will often respond on IRC.

I've bought several games through Impulse so I'm aware of how the client works; I was hoping for clarification on how games that employ GOO sold through Impulse differ from games sold through Impulse that do not employ GOO. I guess I'm just failing to see the distinction between Impulse/GOO and pretty much any other online authentication based DRM.
If there's ever a game on Impulse that I'm particularly interested in and isn't below my $20 cut-off price for games I consider rentals then I probably will see if they can offer further insight into the matter, but for the moment trying to wring answers out of them isn't really worth my time. My hope was that since you seem to be of the honest opinion that GOO is significantly different from other DRM systems to date that you could explain just what makes it so different, to a greater extent than the "It's different. Really. Trust us!" ambiguities that have composed all of Stardock's press releases on the matter.

I've linked you to articles and provided insight into how the system is different from other DRM on the market. What else would you have me do?
Here is another comparison of GOO vs. SecuROM & Steam:
Program Architecture
SecuROM: Installs an application on your system that is used for activation and remains after a game is removed; may interfere with system processes and cause technical problems
GOO: Exists as a wrapper for the game executable, and therefore does not install anything on your system, nor does it remain following an uninstall; does not break the system or the game
Steam: Requires a separate client that runs in the background
Activation Limits
SecuROM: Activation limits optional
GOO: Activation tied to an account, so there are no limits
Steam: [same as GOO]
License
SecuROM: Non-transferrable
GOO: Transfers optional
Steam: Non-transferrable
Legacy
SecuROM: If the activation servers go offline, the game cannot be installed
GOO: Activation services can be transferred to other providers, such as a digital store or a game's publisher
Steam: If Steam goes offline, the game cannot be installed
Client
SecuROM: None
GOO: None, but integrates well with Impulse
Steam: Steam client must be running to download, install, update, and play games
Game Updates
SecuROM: Optional
GOO: Optional
Steam: Forced unless user toggles offline mode
***Please keep in mind that GOO is not Impulse. This is a key difference between Steam and Impulse: any game purchased on Steam has DRM (Steam itself), but not every game purchased on Impulse has DRM. Stardock does not place DRM on top of existing DRM, nor does it place DRM on titles that publishers greenlight as DRM-free.
If you still think that GOO is like any other DRM system, I can't help you. The contrast between GOO and its competitors is strong.

The many questions I asked were to try to drill down into just how GOO, in practice, actually works, to see just what fundamental differences, if any, exist between it and the many other online authentication systems that have been implemented to date. My personal concern with all such systems is that my ability to play or install the game may be revoked at some point in the future. Is there anything about GOO that addresses this concern without requiring me to trust Stardock (or some other entity) to still have their activation servers running 10 years down the line?
Your list of differences looks to differentiate GOO from some of the other DRM systems based on theory, but in practice I'm still not seeing much of a difference. For example, you make the claim that GOO does not require any additional programs or drivers to be installed, but currently just about all the games that use GOO are sold through Impulse and thus require the Impulse client to be installed to install or update the games. On transferability I've seen the claim made that GOO allows copies to be resold, but in another discussion I had with someone on this matter it seems that it's actually only pseudo-transferable, in that you can only "sell" it back to the distributor (they pay you some money and then revoke your license); additionally, to date I haven't seen any cases of this claimed functionality actually implemented for any games. And with regards to legacy GOO seems no different from other online authentication systems as you're still depending on someone keeping the activation servers online to be able to install the game.
I know I've already asked this, but since pretty much all the implementations of GOO thus far are through the Impulse client, just what exact is the difference between GOO and Impulse, in practice?
I'll also reiterate that I've heard pretty much all the theory and marketing pitches surrounding GOO, and while it sounds decent enough on the surface my reservations surround the actual details of the implementation, which so far doesn't seem to really distinguish it from other generic online activation DRM systems.

Well, I'll be honest: because GOO only exists on Impulse at this time, you will have to wait for Majesty 2, the first game to contain GOO outside of Impulse, to judge the system.
You are hung up on your theorhetical considerations versus real use dilemma. The system is designed a certain way, and you are aware of how it works. It appears that you do not care how it works, but rather if it works. Until you try a non-Impulse GOO game, I doubt that I can persuade you in any way.
EDIT: I encourage you to get involved with content providers if you are passionate about DRM and consumer rights. Some of these providers, such as Stardock, are more than willing to engage in dialogue with thoughtful consumers.

On the contrary, I have little interest in the theoretical considerations and am hung up on the practicalities of the implementation. Ideas are a dime a dozen, talk is cheap, and so on and so forth; the only thing that actually matters is how the actual system that results actually works. And as a customer my only real concern is what I'm actually getting for my money, and if it's worth the asking price; naturally I need a pretty clear idea of how the DRM system on a product works in order to evaluate just what I'm getting, and what the potential pitfalls are. But you're quite right that without an actual implementation of the system it will be near-impossible to sell me on the theoretical advantages, and since it's looking like an implementation that differentiates itself from Impulse isn't yet out on the market I'll be sitting back with my usual "wait and see" approach. Although with any luck it won't be all that long before a game that implements the system, that I'm interested in, and that's under the price I'm willing to pay for an unknown DRM system so that I can actually evaluate GOO for myself.

Well, when Majesty 2 comes out:
I will write a letter about its use of GOO / and sign it with a kiss, just for you.

Haha, well as long as it's signed with a kiss, otherwise I'm not interested. ;) But to be serious I would be most interested in hearing the details on the implementation, so a topic on the matter or an addendum to this thread would be most welcome when the information becomes available. And thanks for the information you've provided thus far as well.

If I remember, I will try to get some details from Stardock at some point, so I can post them here.

Thanks for the info. I just took a brief look through the official forums but there doesn't seem to be much mention of GOO (although a fair number of people having problems with GFWL... go figure). I'll just have to see if any specifics about the implementation surface as time goes on.

I was actually a bit surprised that Stardock didn't really make any sort of deal about another publisher trying their new system. Did they even mention the fact anywhere??

Now assuming we are not talking about goo games, If I were to back up the exe file of a game on a disk and install it on a computer with no internet, would it work? That is the main thing I want to know about impulse.

So far as I know, you really can't. You CAN archive your installed games, but the archive is in a format that can only run via Impulse. Whether Impulse could be cut off from the Internet and still use that archive I don't know.

I dislike Impulse, it's more region-restricted than Steam and equally overpriced for me.