2) That enemies can only fully notice the player at the 100 TU turn changes, regardless of their stats, and feels almost 4th wall breaking, compared to the otherwise very fluid and alive feel of the world.
Not sure where you got that info, since the way sight knowledge works is as you might expect: enemies notice you on their turn, whenever that is.
Both of you are correct? Enemies can spot you only on their turn, but all of their turns occur at Cogmind's 100 TU turn changes.
Abusing it isn't even as tedious as you seem to think. When you're moving very fast, all events happen at the same time. Like when you move at 20 TU, all other robots move at your 5th move, your energy rises at your 5th move, and your heat dissipates at your 5th move. This means that the game is making it APPARENT for when you can be spotted/shot at and it constantly reminds you, every 5 moves.
So, during my recent speedrun attempts, I actually started counting moves until the next turn change when there are hostiles in view, so I can duck into cover/use robots as cover at the right time. I literally count "1,2,3,4,duck,1,2,3,4,duck,...".
And when 100 isn't divisible by my movespeed, that's not a problem either. At 17 speed I have (rarely) 5 or (usually) 6 moves, so it's "1,2,3,4, duck (if they didn't act, duck again!), ...".
I kind of feel bad for bringing this topic to attention, because it's not very significant quirk of this time system, but it seems it is very hard to change (it affects so many other things that probably bugs will pop up everywhere if this system is changed). When I posted this, I thought that changing this system would be simple. But now I know that is not the case, so IMO it's better for Kyzrati to focus on other changes to the game!