Law enforcement will react to you based on how you/your character is throughout the roleplay. For the most part, they will be under direct line of the mayor, who you will soon find is not very...[i]fond[/i] of powered people. You will be a member within the registered squad of heroes, but until you are of a sufficient legend level - no-one will particularly care about what your character is doing, [i]unless[/i] they make a mistake. It all depends on where your legend level is. 

Robotic prosthetic's are completely alright. As it does take place in 2048, there will be some technological advancements - nothing too severe, but seeing as robotic prosthetic's are already into play as of now, I see no problem with them.