For the research screen, I'd like to see a couple more sorting options. In particular, sorting by research field and sorting by scientist skill would both be nice sometimes. Also, I want the option to see future techs, like VB6 had.
Prototypes are really awesome, but I have occasionally felt limited by the lack of them for some things. Can we get the option to create (FP) items for the non-researched components, like flag bridges, cargo shuttles, fuel tanks, and so on? Also, prototype ground units would be kind of nice.
The default organization of ship components in the build menu is a bit chaotic, IMO. I'd love to see some options to re-organize them. Something like the new fleet interface would be nice, with drag-and-drop and user-defined categories, but I know that's probably overkill. Even just having checkboxes for showing military and commercial components might be nice, though, so I can ignore all the weapons etc. on my freighters, and ignore all the cargo bays etc. on my battleships.
Crew-Served Anti-Personnel on infantry provide 6x the firepower at 2. 4x the cost and 2. 4x the size compared to Personal weapons making them the overall more efficient option. I think it would be a better trade off if they cost 6-8x as much instead making it a trade off between taking the more resource efficient personal weapons or the more space efficient Crew-Served Anti-Personnel. Nerfing the AP of CSAP to 1 less than personal weapons could also be another option for balancing.
It's not as obvious as you might think. A 12-ton machine gunner has no more HP than a 5-ton infantryman, so they lose 2.4x as much cost and 2.4x as much combat power when they're attacked. Equal-sized forces of PW infantry and CAP infantry are almost equally matched. 100 machine-gunners can kill 600 riflemen=3000 tons (ignoring hit chances, tech differences, etc.), and 240 riflemen can kill 240 machine-gunners=2880 tons. The machine gunners also use more supply in the process.
When re-training scientists to a new field their research bonus is reduced by 75%. However this lets you generate scientists with bonuses which aren't a multiple of 5, could it be changed so that it rounds (or rounds down) to the nearest 5? Given scientists gain bonuses in steps of 5 it would stop them from being permanently 'the odd one out'.
Alternately, I'd like to see them go to a multiple of 5% the next time they upgrade. Just change the chances accordingly. For example, if a 15% scientist goes to a different field, they'll become a 4% scientist. The next upgrade should bring them to 5%, but because it's 1/5 the size, it should be 5x more likely. (This may be too much work, but if it's practical, it satisfies both my OCD and my desire to prevent obvious loopholes with the rules)