A small amount of oil in the cylinders and turned over manually, as suggested, wouldn't be a bad idea. Marvel mystery oil has been a favorite for tasks like that for decades.
Throttle cables may be ok. If they don't bind at all, a lube job may be all it takes.
It sounds like you've taken care of the external fuel system about as well as anyone could. Since the tank now has fresh fuel in it, I'd try to give it a go without disassembling the throttle bodies. At this point, you've got nothing to lose. At least you won't be pumping nasty old fuel into the injectors, since you've flushed everything. If it doesn't run, or only runs on one cylinder, you then know you'll have to dig in. If it runs reasonably well, a tank or two of well-treated fuel may finish the cleaning job. As an Amsoil dealer, I use Amsoil Quickshot (https://www.amsoil.com/shop/by-produ...-EA?zo=5889580
), but there are many options that people swear by, like Seafoam and Berryman's B12. If it ran two years ago when you did the last oil change, it may not be as bad as you think. Speaking of which, fresh oil and a filter seems like good insurance against a bunch of moisture in what's in there. Hot and cold cycles under a tarp can cause a lot of condensation.
The tires are good candidates for replacement, since they're at least 5 years old now. But, if they hold air and aren't dry-cracked from sitting, you can probably ride around on them a little while you sort out the fuel system.
See if you can get it running, and go from there. People have resurrected bikes worse than yours successfully, so don't overthink it. Check the front and rear brake operation on a lift or centerstand if you have one. If the calipers are still operating and releasing freely, great. Fresh fluid run through both front and rear would be a good idea. Brake fluid is hygroscopic, and will attract some moisture over time. Flush it out with some fresh fluid.
Best of luck getting it back on the road!