#1
i practice about 20 songs at once, each day i play through each being happy with the stuff i can play comfortable then picking out the prhases giving me trouble practicing it a few times before i move to the next song and do the same thing, is this too much for a learning effect for my brain?
#2
sounds fine. Keep it up! Also, if you want to improve, focus on the stuff you find hard. If you want to have fun, relax or whatever, play the stuff you know well. A mix is best.