Do we have to queue if we have person in a wheelchair?

This mostly depends on the attraction. There are usually wheelchair locations where a cast member can help a wheelchair guest plus their family onto the attraction however usually the person into wheelchair has to transfer. On other attractions however if they are wheelchair accessible,such as mickeys philharmagic and princess fairytale hall, unless you have a fastpass or a DAS pass the wheelchair and party but remain together in the standard queue

No they let you mostly in a fast way. They are very frienly and helpful.

So nice place, you all should visit there.