charge them as slow as you can stand to. fast charging isn't good for NiMH, if you have time to charge them over 4-8hr why charge them in 1? generally speaking i try not to go over 0.5c but as people said, different cells are rated differently - the Turnigy LSDs are only rated about 0.4c charge, for example.

battery holders ala radio shack are pretty cheap, do the job, etc. You could probably bodge something with a tube and a couple of springs but it isnt worth it

failing proper battery holders, find some broken or otherwise worthless piece of electronics which takes the right amount of aaa's and chop the battery tray out of it