I realize this is an old thread, but I've been raising worms for 2 years now and thought I should throw in a few of my learned experiences:
Best thing anyone can do, is to get their bin/farm set up correctly and then leave it alone. I haven't touched my worms for 2 months until today- no food, no watering, no scraps added, nothing. Figured they were all dead. Stirred up the bin a bit- thousands of the little buggers and thriving. I did add some new newspaper (soaked and wrung) and did add some vegetable matter. Probably won't look at them again until spring.
Heat- Yes, heat will kill them, BUT, if your bin is set up right, they will find the cool spot they need to live through it. My bin is about 10 feet from my woodstove, and the stove has been running hot for the past month. No issues. The bin is "self insulating".
Find out what they like and feed that to them. Find out what they don't like and don't feed that to them (it will just rot). My worms love cantalope and watermelon rinds, lettuce, newspaper, apple skins and cores, coffee grinds, tea bags, etc. They don't seem to like orange peels, potato peels or any thing that seems to be high acid.
Once you buy your initial set of worms (you can find them a lot cheaper than $38/lb if you look on line), and you get them established, you are set for life (assuming you have the conditions right. If I ever get 'round to it, I'm going to start another bin and just take some from the old bin and move em over. Remember, it's like everything else in nature: a certain amount of habitat can only support a certain amount of life. If your bin gets crowded then some will have to die off.
You can control flies and other unwanted guests a few ways. First, bury all scraps under a few inches of newspaper. That usually takes care of it. If still problems, add some Diatomaceous Earth. Doesn't affect the worms at all, but shreds the outsides of most other unwanted critters.
Last note (for now anyway): When I first started my bin, I was deathly afraid that they would all crawl out in the middle of the night, so I put a lid on (holes were drilled in it). Every morning, there were worms around the top and on the bottom of the lid. After I questioned some other wormers about it, they recommended "no lid". Turns out, there would be condesation formed when the lid was on, and the worms like to explore. Now with no lid, it is dry on top and on the sides, and they don't like that, so no more "adventuring".
Hope this info is beneficial. I used to be really active with my worms, but other things have been priorities lately. Luckily, they just keep doing their thing and in the spring I will have about a half a bin of super worm castings.