Some of my users are complaining that it's hard to tell what's going on sometimes becasue of that small horizontal rule between a user's post and their signature. 

Is there any way to alter that and possibly put a couple of   "<p>" tags in there to drop the signature a bit?

Also what tag in the css sheet controls the post font when you open up a thread?  I've tried several. 

I agree with you... I added a 10px line between each users posts and that made it a lot easier for them to read... with the horizontal rule and the line between each user's post it was kind of hard  to tell the signatures from the next post because the lines looked exactly the same...

Thanks for the css tip.