Only if the application is programmed to allow it. I have a Desire running 2.2 and only a quarter of the apps I use allow it. Google itself is the biggest offender, Maps won't run from SD and that's about 10mb.
Yes, maps and the Facebook app take up loads of space...grr... (I'm an avid FB user)... I deleted the app and lived with the online FB mobile page, but didn't take to it, nor HTCs 'friend stream' pile of pants.
If I could move them to SD, and also have some kind super-battery, I'd be a hppy bunny. As it is, I don't use the cycling apps (endomondo etc) coz of battery issues... I know I could over say a 4-5 hr ride, but prefer to make sure I have power for emergencies if needed.
Charging wise during week, well, I spend most of my days at a desk in front of a PC, so just keep it charging via USB most of the time.