I see the "fireworks" in the save thumbnail/screenshot, but have never seen that on my system and if I load either of them, I still don't see that effect. Since I have never seen that sort of thing, but it is obviously a phenomenon that can occur (given the evidence of the save thumbnails in more than one file), I'm guessing it is particular to the graphics hardware you have. What are your system specs (OS, video card GPU, etc.?) Also, is this 64 bit version or 32 bit version of DX9?
I only have a couple laptop systems to test on and unfortunately, are all relatively low-end graphics with OEM Intel chips. I will send these files to my major partner in ERAS, known as ModernKnight1, to see if he's ever seen that on his system. He plays the game much more than myself and is the primary content provider and a massive bug-finder given how much he plays. But I think he only has AMD systems...anyway, I'll see if he has ever seen it, or can reproduce it.
As for the surrender/tribute problem, I will load the save and research the issue. I do know that the surrender mechanic was kind of "broken" from GOF (it did not exist in COAS and was implemented in GOF 1) and we've tried to fix some of the problems that would sometimes occur, but there may be more work to do...