Jumping up- yea, I hate it. The new puppy does it.. or use to do it. A couple of knees in the chest and now she is leary of it.. at least with me. We had to compromise with my old rat. She can jump up when I invite her to do so and yes, there is a very clear signal for that too.
Scared of the crate? bah. Even dogs who were locked in their crates and abused can be sucessfully retrained to accept the crate. The "fear" is the fact that they want OUT of the crate, not that the crate is killing them. The first night, I wanted to strangle the new puppy. They let her sleep with them at night and I am just not that comfortable letting her do that yet, so she sleeps in the crate. My old rat didn't get to sleep with us until she was at least 4-5 years old. Anyway, she yowled, and howled, and barked, and whined, and scratched, and ripped my curtains down on top of her (that was my bad, I put the crate too close to them). Anyway, now she just whines when she needs to go out. She's learned that whining will just get her a scolding if she doesn't have to potty. She is one smart little shit head. I'll give her that.
Fostering- I have considered it many times. However, I am always worried that I will get WAAAAAY to attached and can't let them go. It wouldn't be fair to the animal if I couldn't let them find the perfect home. I do admire those who can though.