I think the multiple links thing isn't doable - javascript doesn't really have a long-term memory, and afaik a bookmarklet can only affect a) the page it's called from and b) any pages it opens. You can do it with browser extensions, though, I think? I know the metafandom people had one for link-compiling at some point, and at one point Opera even had a built-in "scratchpad" sort of thing that was good for that. But I don't do browser extensions. :P

I don't know if the open-in-new-tab is doable or not! I have just remembered that was also on my list of things to try, but the first time I tried it wasn't as easy as I was hoping and then I moved on. Maybe I will look at that a little closer.

(I feel like at some point we will have to have actual multiple versions running at once, since not everybody would want a new tab, and I was also thinking maybe a version with more condensed formatting for people who do really long linkspams....)(But! I am not supposed to be messing with it anymore! Other things!)