Hope my firm decision on the mirrors will not provoke the same reaction as the current Dawes Fixie no brake thread fiasco, I am new to the world of touring!!
I sure if you tried as hard as possible, you couldn't be anywhere near as annoying and offensive
Good luck with the seatpost. Don't be too tempted to lever open the seatclamp lug with a screw-driver, which is one of the only reasons anyone would have removed the bolt. This can help sometimes, but as you've probably got at least 10" of seatpost inside the seat-tube, splaying the top out won't help and you might just end up cracking the paintwork.
One reason for opening the top end slightly is to help penetrating oil find its way down. I'd recommend you squirt a load of WD40 there now and give it time to soak for a few days. No matter which removal method you adopt, you'll need to have done this anyway.
It could be that someone's possibly installed a seatpost that's slightly too large in diameter. As stated, check out Sheldon. If you are quite new to bike stuff, read all his mechanic's guides - if you didn't already know it's quite a gospel.
Willi Moore Tourer 531c / Record (~1985)
Dawes Jackal (1988) - Sold
Kona Explosif (1989) - Stolen
Dawes Stratos (1991) -Sold
GIOS Compact Pro (1993) - Sold
Trek 8500 (2001) - Sold
MBK SuperPro (2002)
Dave Hinde Airplane (2003)
Reise Und Muller Birdy (2007)
Cove Stiffee (2009)
Marin Toscana CX (2010)
Giant Trance X1 (2011)