Sadly you are correct. The VP position has no power other than what the Prez allows. It is primarily a ceremonial position. Picking Ryan was good but it will not "bridge" the gap with the conservative base. The base is not that stupid. And yes, Ryan is a 'go-along to get-along' politician. He won't go against the one who brings him to the dance.
The usual role of the VP candidate is to play attack dog. I think Ryan will be well suited for this role. I expect Romney will try and stay above the fray and act presidential. Time will tell.