I have a ea with ef bottom end, shaved au head with steel gasket and a surecam custom cam, now what i'm wondering is if i used my spare adjustable fuel regulator and gave it more timing will i gain some extra power?

Of course, but you'll have to run better fuel or it'll detonate with advanced timing.

I am wondering this as well. After dyno day on saturday, the dude said our Falcons can respond well to 5 - 10 (???) degrees advanced timing. At what point do we have to start considering 95 octane or even premium 98?

1/ Is the a general rule? rather than wait to hear and feel the knocking / pinging sound?

2/ I was gonna wait until my 1636 finally goes in. Would this be the time to bump the dizzy 5'degrees? (Autotech would tune it not me.. but just curious atm)

EF/ELs can handle a few more degrees base with a twist of the dizzy, but they don't seem to respond to it that well, maybe because of higher comp, I dunno.

EA-EDs with stock compression f**k love it but, especially with a cam, increased overlap effectively reduces compression.
I've got about 18degrees base in mine with a Dev3HL, 8 degrees over the standard 10, and it doesn't ping on 91.
Theres no hard and fast rule but, every engine is different, some might have had the head decked 3 times from head gasket changes, so just have a play with it.

As for adjusting fuel pressure with reg, yes you could lean it out a bit, and it would probably f**k hammer for a little bit, but the stock ECU has a tendency to learn around small fuel pressure changes by looking at o2 sensor readings.
How much it can compensate, I don't know.
Probably more then you can reduce pressure without effecting injector spray pattern.