Find someone you can get along with. You will be spending quite a bit of time with them. Not sure if this is your first purchase, but with regards to experience I really think that as a first time buyer you may actually benefit from a less experienced agent that has more time to show you around. Not brand new, but someone that has done a few deals in your area.

The agency has absolutely nothing to do with it in my opinion. Your working with the agent and they are the one you will want to do everything in your best interest. Small agency or large agency you want someone you can trust.

tips? I would say ask your friends who have purchased in the area or go to open houses in the area.

With regards to credit at sale it would seem ethical for the credit to come from both sides of the transaction equally as opposed the the buyers agent that probably spent more time with you and would be advising you throughout the transaction.