No risk, custom firmware has recovery mode so if you semi brick which is very unlikely you can recover!. Ta-082 mobo is fine... Upgrade!!! lol in my opinion 3.03 oe-c is the shit.
heres the link psp's links are awesome and work fine
http://www.pspmod.com/forums/showthr...irmware+thread (GTA:LCS downgrade region?)