I know my reading abilities were left home that day, so liberties got mismanaged for no reason.
I still seem to struggle with my direction of play. For some reason I can’t judge what AI is trying to say to me, any big things popping out to more experienced eyes?
I left a few quick comments, but the main points are that
I tried SL, but I don’t understand which stones…
I mean, for instance you peeped at a one-point jump. Your stone N5 is a stone which may help later, but don’t try to save it immediately.
I see, thank you 
The idea of Kikashi is to play a move that forces a defensive answer from the opponent, and provided they do defend, this A for B exchange has no drawbacks whatsoever for you.
So if this exchange destroys some future potential, it would not be considered Kikashi, but rather Aji Keshi (e.g. peeping at a potential cutting point).
Strictly speaking, all moves destroy some future potential, but if the advantages outweigh the drawbacks, of course it is still good to go for such an exchange.
I believe the perhaps most prominent example for what is widely considered Kikashi is peeping at a tigers mouth.
As for the saying, its not that developing Kikashi stones into a bigger group is inheriently bad. In fact that can be good sometimes. However, contrary to most other moves, one usually doesn’t play Kikashi moves with the intention to add stones to it later. Its just to prompt an immediate answer from the opponent which you believe to be beneficial to you, with little to no drawbacks.
Would it be considered as either kikashi or aji keshi if it’s a forcing move during a ko fight? Or those terms don’t apply in that situation?
I haven’t encountered the word Kikashi in the context of a ko fight, maybe then it would be called a ko threat (but not 100% sure). But a ko threat can certainly be Aji Keshi, e.g. if it makes the opponent defend one of their weak points.
No problem to use a kikashi as ko threat.
For some extended concepts, kikashi value has a lot to do with good timing.
Move 43
Purpose of 1 should have been to capture the square marked stone but you went on to save x marked stone which is already surrounded by white stones.
Be consistent. Don’t try to save almost dead stones.
Move 31
x marked stones are already weakened and not important. Saving this is a waste of a move unless there’s a good reason.
Move 71
You are building up your debts that’s what you should feel. Leaving this many cutting points and keep proceeding will lead your group to break up in air. Also this move is ‘crawl on the wall’ type move which is what you should avoid.
Move 21
This one is not so bad compared to others. But this is ‘crawl on the wall’ move. you should at least feel uneasy doing this.