I have been doing this for eleven years, played FO3 and NV on older PCs with no problems. I also have the three Elderscrolls mentioned above [average 100 plugins] plus Enderal  on Win 8.1, Lenovo Y70 with 16ram.
FO3 has 6 plugins, DLC and Updated UF3P all in order. I generally examine each plugin with it's required ESM. With exception of two shacks, the rest petty items an a couple of followers, all of which use just one esm in a vanilla game. There are a few more I'm still looking for.
Each plugin and master loads up, but when I look for the shack, loading the map = ctd. Open the petty item box or any vanilla container = ctd. NPC and Follower box opens but examine the = ctd. I have yet to do a Bash patch or a LODgen.
Tonight I will see If I can access the esm content.
How are you launching the Geck ? When in doubt go back to the .exe in the file location for test.
But when you say you are trying to find a stable version of the Geck for download.
Says you have downloaded and re-installed the geck already.
And that in its self done wrong , or missing a step . will make it not work.
So ... you have to take a breath , and think backwards what was done.
Only you know. And if you don't ,,, then of course all we on the other end of this conversation can do is tell you how to start over CLEANLY .
Which is ... you just buy a new computer .... LOL kidding ... but you see what I mean ?