I get that a game like Stellaris has to do a lot of loading up front compared to other games, so I expect that... however, there are a couple things that seem off to me.

1: When I go to load a game for the first time, it literally takes like 3 minutes before I see the selection screen
2: After I start playing a game, after unpausing it, a few minutes later, the game will freeze for another 2-4 minutes, during which time the HDD activity LED on my system is near constant. After that, it runs fine until it eventually crashes, but that's another topic.

My system should be more than a match for Stellaris

CPU: i7-4770
RAM: 16GB (about 60% utilization pre-Stellaris launch)
Video: GTX 960 4GB
Driver: 418.91
OS: Windows 10 (all major and minor updates)

No mods, only the free horizons DLC (wanted to make sure I'd like the game before buying the expansions, and didn't want to abuse the generous GOG return policy). The only out of the ordinary thing I do is use the app MouseJail to keep the cursor on one screen.

I've tried excluding the Galaxy client game directory from AV scans, the Stellaris executable specifically, as well as the MouseJail executable. Initially I installed Stellaris on an external USB 3.0 HDD, but have since reinstalled it on the boot drive, and in both cases I get the same behavior. It seems a little less pronounced on the boot drive. I haven't (yet) tried disabling the AV scanner entirely while playing, but wondering if anyone else has any thoughts, aside from getting a SSD, or if this is just normal.

This is sadly normal; Stellaris has rather long load times, especially to start up the game. This, on the other hand, is not normal. The game definitely has slow-down issues in the late-game when populations get huge, but it doesn't outright crash or freeze on me.

I would suggest making a support request; freezing and crashing isn't normal.

To be specific, I mean when I click the "Load Game" button on the main screen and the time I see a selection of past saves. Again, just to be specific, the game eventually starts working again. I've been sending the crash reports when prompted upon restarting the game, but who knows if anyone even bothers looking at those over at Paradox.

For me it's about a 1 second delay, so this is definitely unusual. Freezing for minutes on end isn't normal. I suppose you could take the perspective that it's better than outright crashing, but it's still not normal or acceptable behavior from the game.

the game is C## so if you pause it then that doesn't really pause the game... and so having it paused for a long time will strain your system

the time at start up is because Paradox made it look for a network... nothing can be done about that now

It does crash... eventually... just maybe an hour or so later. While annoying, it does function as a reminder to take a break. Guess I'll see if I can find a place to submit some kind of support ticket to Paradox.

That is not true at all. There certainly will still be some overhead in the background even when paused, but pausing the game will substantially lower your CPU usage.

I was actually curious as to how much pausing the game affected CPU utilization so I loaded task manager and looked at my CPU utilization. With the game paused my CPU was hovering around 13% utilization, and when the game was running on fastest (on a fairly large galaxy) it ping-ponged between 25%-40% utilization. If you purchased within the last 30 days, you might also want to put in a support request through GOG. If your issue can't be resolved, you can potentially get a refund, but only if you submit a support ticket within 30 days of purchase.

A friend of mine once had similar problems with another game which were caused by a corrupted sector on his HDD. You might want to scan for those when you have an hour or two free time, just to make sure...

that is the Paradox web browser framework and I would first assume your antivirus or that the network you have is lagging bad i.e, slow internet due to scans or other downloads

p.s, report it to Paradox as Gog has bugger all to do with fixing | patching games once they go live

I have been trying to find where you report bugs to Paradox, but they do not make it easy. Their "helpdesk" website is basically just a link to a bunch of Steam forum posts. Supposedly if you link your Steam account to your Paradox account there's a hidden bug reporting forum, but damned if I can find it even after that.

I'm thinking the issue has something to do with a bug in Stellaris though. Looking at the error log for the game, there are a bunch of SDL Out of memory errors right before the game crashes. I'd try just updating the SDL library, but you kind of can't on Windows.

yes Paradox does talk to your system during play ...[assuming you sign in] if for example you kill the Kaine then that earns you a badge

it sounds like your system is blocking ports it should not be blocking i.e, Proxy server, [actual physical] firewall or VPN spring to mind as possible reasons but the bottom line is that this is something happening only to a few people... maybe just you

p.s, just make a post on their Stellaris forum with Bug in the title... Paradox forum is not the same account system as Paradox games, I have three different Ussnorway accounts with them and only one is linked to a game