I prefer to send myself a tell rather than using an extra chat channel. ';tell yourservername.yourname Message' works just fine, and you never need to worry about making sure your channel numbers remain the same - hehe.
On the timer thing, I think I'd probably try to get hold of a mp3 editor and add a X second blank sound then a wearing off message (so you would hear 'Slowed', X seconds pause, 'Slow wearing off'). It might interfere with playing other audio files, but if it worked then you would be able to use other hotkeys rather than being locked out for the X seconds you have on your /pause counter.
If someone tests this then please do post the results.
Oh, handy hint if you don't want to clutter up your real estate. Once you associate a button with a hotkey slot you don't need to have the hotbar visible. By that I mean you could set up number 1 to trigger bar 1, slot 1 and then use the EQ/actions menu to hide the hotbar. Not relevant I know, but I noticed that a few days ago and thought I'd share for the benefit of anyone who didn't know this and would find it useful
Katt