n00b-ish question regarding downgrading: does it matter which region's firmware you use? For example, if you have a Japanese PSP with firmware updates from Sony Japan and you use the downgrader (which I believer is based on US or EU firmware), is the risk of bricking higher?

I think I know which service he's talking about (although I too forget what the name is). Apparently, it's limited to the Klang Valley. Games are sent and picked up via courier if you can't make it to their shop. There's a limit to how many games you can check out at any one time, but no time limit on how long you can hold them. Something like that.