Okay, I have been working on this for the last three nights and just finished everything. I put the file in a zip and uploaded it
here for now; you can put it into a rar sfx or whatever. I did everything I listed earlier as well as several other things I noticed:
I redid most of the laserglows and newglos with somewhat weaker blurs, as many of them had excessively strong blurs.
The sunglow designs were not good for their purposes. Their brightness levels and shapes/sizes caused them to heavily discolor the suns behind them. An appropriately colored and scaled simple lens flare is all that is needed here, which is what I did. I found a different use for those sunglow graphics though; see below.
Most of the suns were very blurry at their existing sizes, so I shortened them a bit, enough to fit in 256x256 images, without losing any quality. The red one is the only one that makes use of the higher resolution, so that one is a 512x512 image.
I was going to just size the beamglows back but then decided that these didn't look much better than the originals. I instead made some modifications to the sunglows and used those here. I think it was a few hours well spent, as these look much better now. It also turns out that no quality is lost by converting these to 256 colors, so that was done.
The positions of some ships in sunsathanas01 were changed to have them all face the center of the image; their centerpoint used to be somewhat offset to the right. There is still one issue though: the six Sathanas in the center area look quite crappy compared to the rest. I don't know how to fix this however, as it looks like the central six were done by just taking screenshots in Modelview while the others were rendered using some antialiasing technique.
For the thrusters, I settled on what I had suggested earlier with some changes. Most of these images had lots of problems with sizes and scales and many were either too blurry or too grainy, so that is now corrected. I used almost all of the originals that weren't either very blurry or too small when scaled properly, and all the slots were filled up in the end.
I will fix up the Ulysses later today and post it when I am done.