I'll check out that product. The dowel idea is a good one. Didn't even think of that.
No rust on the screws, but I am positive that there's no rot in that corner. Just some stripped screws. Good thought about not going longer. I know that the construction is 2x2, or at least it was advertised that it was.
Epoxy is a good idea. Wouldn't that be a decent fix on its own? Something like quick steel. Drill it out some to clean it up, then put the stuff into the holes good. Epoxy would be better because I can inject it. Then I can simply drill some new pilot holes and reinstall the screws. That may be the route I go.
The screws are not rusty. But that's kind of an irrelevant point because of where I live. At least, I know that the threads aren't rusty.