ET3D: You don't need to install the Steam client to post on the Steam forums or SteamGifts. It's all web based authentication.
SteamGifts doesn't require Steam bought games, far as I know, but it does require a certain value of games which haven't been bundled, which can be a problem if you only have old games (because their current value is low and many old games have already been bundled).
Still, there are a lot of people here (like me) with SteamGifts accounts, and even a Steam group for GOG gifting and a
thread here for it, so you can just send the keys to someone to make giveaways with.
Well, l tried once to make an account on steamgifts (a couple of months ago I think, when it felt somewhat more insecure to gift steam keys here, because of nes and whatnot), and it told me I needed to have $12 or so in purchases from the Steam store itself, if I recall well. In case this is of any help, only 2 games I have registered with my steam account are Empire Total War and Deus Ex Human Revolution, so not very new but not very old either.
As for passing the keys along to someone else, I could theoretically do that, but I generally prefer to host my own giveaways, so I that I have control over the procedure (I've only given keys once to the shabby games shelter -this was before Impaler stopped accepting them because of all the scammers- and these keys were keys of games I was certain I wouldn't be able to get rid of in my own giveaways). Anyways, my point was I have way too many Steam keys I have no use for, and getting encumbered with others I didn't want in the 1st place (as they didn't come with drm-free equivalents) that would also definitely lose value very soon and wouldn't thus be very giftable, isn't a prospect that excites me. Anyways, regarding the bundle I'll just pay below $1, as was already proposed to me (only thing I want is the books after all), and will think later whether I want to send some keys of mine to someone else via chat so they can gift them on steamgifts and whatnot...
P.S. Which reminds me, out of the handful of people that have entered for my 2 latest giveaways, a couple were scammers/suspicious people, hence my hesitation to get more steam keys ...
P.S. 2 Just a pointer in advance, don't advise me to give me to TBBobb, I already know of its existence, and at any rate I'll decide what I'll do with what I already have...