make sure piping is in order, they should check for any moisture under home or between walls.  

You could argue that you're worse off with an underlayment because it could add more "play" to the floors and work the locking mechanism loose.You might want an underlayment over concrete though or if you have a moisture problem but I doubt even in this case that it would make a significant difference.

Many older brick homes survive for a long time after settling, but if moisture is getting in through the bricks, you could be looking at repointing the buildings.  

if the weed block works and I get it sealed, is the seal solid enough  to prevent further weed penetration?  

That is one I'll want to think about taking care of as any moisture indoors is bad bad bad.I too have some concerns with my bathtub/shower.

don't be afraid to spend time on a ladder poking everything that has increased moisture deterioration risk.

The $2,000 or so it is going to cost is minor, when purchasing a property that is north of $1million.I personally wouldn't be as concerned about the mold, unless you know there are water/moisture issues.

Electrical wires are usually good unless it was exposed to moisture then it can be brittle.

I'm assuming from your last post that the actual penetrations from your first post are probably plumbing vents, which don't require any kind of cap.

It's full of mold, there's moisture in the walls, it's been there for months, she's made multiple complaints to us, we refuse to fix it, etc....She went as far as to call and make a complaint to the town health department.First off, NONE of that is the case.