1) Hm. I thought it was set to 12 hours between double posting (I remember changing it from something absurdly short), didn't realise it seemingly applied to moderators also. Might be worth me seeing if I can allow anyone with staff to bypass the check, if not, I'll disable it altogether. On a side note, you reminded me to add an extra 'Local Moderator' group eventually, complete with its own blue colour
2) You seemingly figured that one out already, the only difference here being is that stickies aren't split between tables. I feel like phpBB might have such an option to allow stickies to be 'highlighted' as stickies better (putting them in a separate table if I'm remembering rightly), so it's certainly something I'll look into as I'd like to see that myself.
3) Not sure what you mean by URL shortening, do you mean the way the URLs are written on the forums in general or something else like linking directly to a post being somehow awkward?
4) As long as this is something that can be disabled by the user in the control panel, I don't mind implementing a mod that does that.
I thanks'd your post by the way, since it's relatively constructively written and I'm also glad to see you here! Welcome aboard