No do not use spray can primer its garbage compared to the real stuff.

Yes you can use filler or putty over the 2k.

Recaot entire hood and block sand w/ guide coat.

my 2 cents worth.

Take care,
Rick
68 Coronet R/T 440 & 68 Charger 528 Hemi,and 5 Challengers! 6 cyl, 318, 360, 383, 451