What is it that makes bacon so delicious?
The big missing thing in your description (fat, salt, smoke) is umami. You can see this in bacon-flavored products. For example, bacon salt (click on a "nutritional info" link) contains monosodium glutamate.

So if you want to make something bacon-flavored, short of using bacon (and possibly draining away a lot of fat), you're generally going to be looking for source of umami; see "What foods are high in umami?" or "What is a good vegetarian source of umami flavour?".

Also, bacon is definitely not acidic, and perhaps slightly sweet. This means, for example, tomatoes are probably not a good way to get the umami, and that whatever you do, you might try adding a tiny touch of sugar to bring out the flavor a little more. Things like shitake mushrooms and nori seem like better flavor matches. (If you've had furikake this shouldn't be too surprising.)