I hope you're not arguing for complete removal of infrastructure researches, (if you are, I disagree with you), but rather for something I've brought up before, namely changing the upper limit of 150 to, say, 250 or 300 (which in practice comes down to infinity), by way of one or two additional researches.
As for roid limits, I personally have no problem with the HCT researches. I feel they add a strategic consideration to the game, without needlessly complicating things ("you can only mine 750 roids" is not exactly hard to understand for new players).
I assume that by exile limits, you mean the 48 tick waiting period for galaxy exiles? Can you explain why you wish to change these limits? I've not really got an opinion on this matter, so convince me.
I agree with the rest of your suggestions, and hope PA team have the guts to implement them.