To seal the block walls from water, use a block sealer that has Portland cement in it. UGL Drylock is one of the better products. I used a less expensive product because I had less of a problem. You can also buy mold inhibitor to mix into paint if you are going to finish with a coat of paint.
If you have a seam between the walls and floor, you should calk it with a silicon based product.
To test your drains, simply get a bucket of water and try them. But have a shop vac handy if they don't work. I unplugged my basement drain by using the shop vac on it. Pulled out some stones and a half rusted combination lock. I'd like to see a drain cleaner work on that!
Sounds like you found a project that will keep you cool in the basement.