"Submit for review" is such an action, so, yes.
Yes. It's a huge issue. If I didn't have a regular task to manually comb those trackers I don't know if anything would get looked at; I have nothing to point others at other than "just randomly peruse the list of open issues". Trac is hot garbage but I miss it every time I have to look at my not-quite-working ad-hoc query to figure out what the workflow state on everything there is.
That said: if we could get this ALL into github, then we could write ONE query that would be the full review queue for all Twisted org projects. And that would be amazing, a huge upgrade from what we've got now.
Finishing txghbot is probably not a ton of work, but it's not zero either.
-g