What is the maximum length a string loop should be on your bow? I guess what Im trying to say is, can it be too long and affect the flight of the arrow(besides increasing draw length).

the maximum would be to not exceed your draw length by much

No real maximum, I guess in practice however (keeping draw length in mind), the longer the loop you might get further from the peep making it hard to see through.

I wouldn't allow the loop to change your DL. You can start getting into bad shotting habits.

Really, they should be kept as short as possible. Otherwise you're changing your draw length. You buy a bow to fit as far as draw length, poundage and all that to get the most you can out of the machine efficienc wise. If you end up shortening the true draw length to accomodate som long string loop you loose power and efficiency. All you want is enough room to quickly and efficiently hook on you release and not be bumping the nock with the jaws. I even changed releases when I went to the loop.