Yes you can, it's the PSP Go that can't play them.
Yes.
No
If they were to ever make a UMD add-on for the go, it probably would not be cheap and would most likely require its own power source. There would not be much sense in releasing such a device as UMD is fast becoming a dead format. For people who really must have access to a UMD, picking up a PSP3000 instead of the GO would be the way to go.
PSP3000 is hackable. you just need the umd game "Gripshift" to make it hackable. there is a youtube video that explains all of this, but I'm not too sure what it is called. you'll have to find it yourself. soz.
psp 3000 is better. It has a bigger screen, can play umd's and you can access the battery unlike the go. Also, the psp 3000 is $130 while the go is $211 so you would be getting more stuff for less money
no
$130
no to the ps3 though
$145
It allows you to play the UMD game.
A UMD is a Universal Media Disc
Yes :D
You can't do it.