indeed, those vertical lines will make it hard to edit later and they're unnecessary to create the form. There are a lot of ways to terminate edgeloops to reduce this sort of problem. A lot of people use the clavicles to help spread some of those edges you get coming down the neck. These are techniques you'll pick up from practice. Try to avoid adding edges just for the sake of adding them. If they don't really help the form or the deformation, they're usually not necessary. This can make your mesh cleaner.

the anatomy is pretty good, but if you really want to get serious with character modeling you should pick up some anatomy books and learn all of the major bones and muscle groups and the exact relationships between them.
Looking quite nice though, man. Keep it up