Yes. The electric fuel pump is likely too high pressure. Carburetors like 3 to 4 psi

Yes, timing varies slightly with different camshafts. However the A series should never exceed 36 degrees total timing and with a mild cam an A12 should not exceed 32 degrees. The pistons can be damaged. Since the distributor mechanical advance adds 25 degrees, the timing should be set to no more than 7 degrees at 800 rpm.

Now if you are running a big-bore A-series (A14 or A15) add 2 more degrees. And if running a long-duration camshaft add 2 more. But for a mild camshaft profile add zero more (unless by mild you actually mean long duration). Keep in mind that A14 distributors have more advance, so still are set to 7 degrees at idle, depending on the exact distributor (some are set to 10 degrees).