I saw some people put off by how technical the tinkering seemed, so I'm going to overexplain everything. Even a baby could do this:

1. from steam, right click on civ 3, and go to manage -> browse local files
2. go into the Conquests folder, and edit the conquests.ini file with a text editor; add these two lines: KeepRes=1

PlayIntro=0

3. go up a level into (...)/steam/steamapps/common (exact location might depend on your distro), then go into (...)/steam/steamapps/common/Proton 5.0/dist/lib/wine
4. first, rename the file called 5.0/dist/lib/wine/gdi32.dll.so to 5.0/dist/lib/wine/gdi32.dll.so.bak (add .bak on the end)
5. then, download the patched file into this directory. To do this, right click on the file explorer and click on 'Open in terminal'; then, copy and execute this in the terminal:

   curl 'https://bugs.winehq.org/attachment.cgi?id=69209' > gdi32.dll.so

(you can do this without the terminal if you want, just make sure the file has the right name)

Everything above is what I've seen from other people (It's Bryoooooooooon &c.), but I discovered (because I was savescuming) that you can stop the frequent crashes by loading the save file a second time once the world is already loaded. If its still crashing, maybe play for 5 mins, save, and immediately load that save. Turning off the sound effects in the ingame preferences prevented any crackling or looping sfx, but still played the sfx when it was meant to be played. Weird.