Replacing men is a cost. It would add to the value of your table and the playability.
There are sets of the warrior guys you can pickup that fit the dynamo rods, they are the older 5/8 ones not the newer 14mm ones. You can pick those up on ebay for $40 a set plus shipping and the upgrade is noticeable.
New tornado players are about $4.5 + each, sometimes you can get them used cheaper.
If you upgrade the guys you will need pins so whatever deal you go with make sure you figure to pick those up too.
I cant speak to the inner bearing. Some one here will know the best way to deal with that.
Good luck.