Buying a used cargo van, need some advice please

Hi there, I found a 2006 Diesel (6.6L Duramax with 180,000 miles) at a decent price, but it has some rust on it from being up north. I would like your opinions on these pics that the dealer sent me. Any advice would be appreciated.

Is some amount of rust acceptable, or is it best to try and find one with no rust? I don't know how quickly rust spreads and breaks down the metal, nor do I know if the rust is in bad places or acceptable areas. Also, is it possible to just remove the rust? Don't know anything about it, hence this post.

Much thanks- Roy