Like many have said already JAB. Keep your hands high and jab. It may feel a little funny at first (not as comfortable as your hands lower and pounding the bag) but it does get much easier and your properly protected at all times. My big thing as of late is the mirror's. You can learn everything you need to learn by shadowboxing while looking at yourself in the mirror. Go fullspeed and see what you are doing wrong and correct it.

As for the ropes try a simple move. When you feel your back hit the ropes,pivot your front foot and swing your back leg out . This making your entire body more narrow and in an easier countering oppurtunity. DON'T swing your back leg into the opposite side as this will make you more vunerable and be able to get hit much easier.( Jesus easier done than typed I think.)