Welcome to BPO!! I have Daphne, a boxer, who has decided that I will do for her forever home!! She's a rescue. No BP at the moment deciding what I want next! This site is addicting and you will get many ideas.
While teaching him stay, also try teaching him wait. I would tell my GSD to wait and he would stop in mid stride. So maybe try this with Gabe so he doesn't automatically greet people at the door. You may also want to teach him a "boundary" at the door, you know give him a threshold, he can't get within so many feet of the door. I know with my family the crate is their home unless they are going out to potty or play for at least the first year. But that also depends on the dog. One thread on here talks about crate training and one good post pointed out not to let the dog out of the crate just because they're being noisy. They might realize if I make noise I get let out.
The anxiousness is something a lot of dogs do. Don't make it a big deal when you come or go from the office. I would almost ignore my dog when I would come home, for a few minutes until he calmed down some and then I would talk to him. This may or may not work, even at 6 he would get a bit axious whenever I would leave but it wouldn't last that long. You'll get a lot of good advice, much better than mine, from some of the people on here!! But these are some thoughts!!
Oh, and we like pics!! (Yes I know I don't have any)