For this to happen, we'd need a bump button so that users could bump their threads, and various other things which would break if this was implemented. It's not a big deal to report it, and depending on the context correct it if need be.
Sorry, must have missed that part.
The mobile issue is annoying. The best option I see for that is to quote only selected text. So if you have some text selected the quote button or the "insert quote" from the reply page would add only selected text.
That would mean a fair bit of coding from theymos though and unfortunately I don't see it happening too soon.
You could potentially create a userscript to do this, and then do the usual bypass to get a script manager on mobile browsers. At least, with Firefox. I'm not sure with other browsers. I'd take a lot of work to do it via the forum, as I imagine that would break a lot of things, but a userscript should be fairly simple to type up.