Can you explain how you did the cranking compression test?
Not that it matters - because it is what it is - but I'd expect more than 150 psi with that cam and a true 10:1 SCR. For reference, my 9.6:1 SCR (measured) 340 has an intake closing after yours and cranks 170 psi.
Don't be afraid of giving it more initial advance. If it wants it, it wants it. As long as it doesn't buck the starter, you're fine. I run 26 initial and the 340 loves it.