Teaching tricks isn't so hard. I started with Roll over, which I feel is easiest. Have a treat (I like to use freezedried meat treats) in hand, take the ferret, physically roll him/her over and then reward them. Do a few times per session, and do it everyday until they get it. Even a handfed piece of their normal food can be a special treat if coming from mom's hands.
Yes, I do generally discourage people from getting ferrets unless they've done a ton of research, can handle the demand of expensive vet bills, and the demand of needy/sick fuzzies. I am so glad that you have these rescues; I feel like people that help needy ferrets are angels because they are very hard to deal with compared to cats/dogs-but the payoff is so great.
Oh, Dorian, it is a shame that so many irresponsible people take in pets only to turn them out on the doorsteps of pet stores and shelters. Ferrets are really hard to take care of at times-they do exactly what you don't want them to do at exactly the wrong times. They're so fun, but they're also a bundle of trouble. People quickly find that they aren't all fun and games and abandon them.
I wish I had room for all of those unwanted furbabies in my business, but I have to be responsible too and not take more than I can handle. Four is my limit.