Can a reseller register brand on same name where he is reselling if TM expires?

Yes, if the trademark is dead, you can register it in your name.

Yes, you can do that, however, the other person has the first to use right, and they can also file a dispute to get the trademark rights back from you.

Yes, Kallis, if a trademark is expired, then any reseller can register a brand under the same name, but there is a possibility that if the original seller again wants to get a trademark under the same brand name, Amazon will cancel your trademark because the brand owner is someone else and he has a selling history on that brand name. So, I will suggest that you go with some other brand name.