Well, it seems like all of this will sort itself out in time. But I strongly (!) recommend that you work on new music with your new teacher, instead of trying to re-work/re-think your other pieces. After you've settled in with some of these new ideas, you might really appreciate the new person's point of view on repertoire you've studied with someone else, but I think that's a frustrating way to get started. As far as the technical specifics, it's really good to learn how to make as many different sounds or colors as we can. For example, there isn't a right or wrong staccato touch; there are many ways to play separated notes, and you can probably hear that this new way has a different quality of sound from your old way. So that's another option that you'll always have now, and one will suit a moment better than the other. There are more staccato touches that you'll come across over time. The slur question, I just don't quite understand what "up and over" means in this context. But anyway, take heart! and learn all you can, but I would definitely tell the new teacher that you'd like to start some new pieces with him/her. The way to persuade him/her to allow this is to ask the teacher's opinion on what you should be playing! No one can resist that. Good luck!