Sorry to hear that your D80 was stolen, I would hate to have a camera stolen from me!
Here are my answers to your questions:
A) Yes, it would be almost as good, although keep in mind that the D80 is certainly a more advanced camera. Considering that you've used the D80 before, you would already know how to use it if it was purchased. Also, you would probably find the D3000's UI slow to navigate through (Coming from a D80), and the guide mode would be of no use to you. Considering that the cameras both have similar sensors, the IQ would be relatively similar.
B) If you went for the XS, remember that your current Nikkor lens would be of no use to you anymore. Try the three cameras out, and if you like the feel of the Canon better, then it certainly would be the better choice.
C) The D5000 is a wonderful camera, and it shares the advanced sensor of the D90 and D300s. It will add features such as video mode and live view that may be important to you as well. If you combine the D5000 with the Nikkor 35mm F1.8 lens, you'll have a wonderful combo that could get you some great images.
I personally am not a fan of kit lenses, and I would prefer a good fast prime any day, but that's just me and my opinion. Another good lens option would be the Nikkor 50mm F1.8 AF lens, it's a fast prime that should give you about an 80mm range, plus it's cheaper than the kit lenses. Although remember that it would only auto focus if you purchased the D80, considering that the D3000 and the D5000 don't offer a built in AF motor, so you would only do manual focusing.
By the way, thank you for the cookie. It was delicious, especially with the glass of milk that I drank it with!