Wow dude, im amazed at your knoledge so far on the PSP when you say you never started modding it yet, bravo. I want to welcome you to our comfy little nook on the internet.
Oh and you said that you have problems getting your USB to work? I dont have trouble getting it into USB mode useing Connect to PC but if your haveing trouble connect your PSP to the computer, turn your PSP off completely and when you boot it back up hold in your R button to boot up into recovery mode since your running OE-B, you can enable your USB through recovery mode.
Once again welcome to the forums, hope you enjoy your stay.