This is one of those things you need to play around with to fit your specific play.
For me the raise is standard 3 but I may raise it to 4 if its a calling station in the big blind.
Something in the same vein of this is players that see flop bets as weak but 30-40% pot bets as strong. It takes time but some players(usually ones that have played me before) will fold to weak bets as they see them as strong or vice versa. Its a good thing to note for flop play if you see the player often enough.
Back to the button,I tend to keep things standard in that spot. UTG is different and so are the next 2 seats to follow. I may open limp,knowing how bad players see that and let if define what kind of player I may be off one move.
As always it depends on the table dynamics and how you play.
it's situational for me. i will keep it the same for an x amount of time and then change it up. i like to often limp with big hands to disguise and then raise with suited connectors in another spot. the key i think is to recognize what type of players you have to your left so you can speculate how to play them when you are on the button
This is a very random thing. It depends on the table, it depends on the opponent. Many will say that the standard is 3bb, but this is not the rule. It depends on your hand, for example, if you have an AA or KK, things change haahha