I would concur fully in the water pump. They're pretty cheap and if you have no idea when it was last done it might be worth doing. On the other hand, it's not exactly a hard job so you could just give it a thorough look over (check for seepage from th tell-tale hole) and leave well alone. If you do go ahead, a pump is about $50 (at least it was about that in Euros). There are 3 varieties, and it wasn't until I got to the third one that I found out why it really pays to do your homework before making assumptions! If you do change the pump, and it is an easy job, change the tiny metal pipe and the two (I think) banjo bolts in the same area. There's lots of info on the site about how to do it. I think I wrote it up, also, and I'm sure the wiki has an entry or 2.
Final thing you could do, again if unsure about the condition of your car, is get someone to pressure test the radiator as you suggest. I had mine done and it fell to pieces. I would have put it back in the state it was in, which would have eventually led to disaster. It looked fine at the time but the insides were shot. $500 rebuild later (ouch) and all seems well.
I wish I'd replaced my viscous fan clutch when I was there, but didn't bother.
I'm sure there are other things people will suggest, but that's my list.
JH