Because it's classed ACC over reload? No. Hypothetically, you could get more shells on target and thus have a greater chance of getting crits, but I do not believe that classing it as ACC gives it a higher chance of getting crits.

no,

but if you always hit the deck especially the center you will have a chance doing some crit, but i don't know if this is true,

but classing on acc huge gunner doesn't mean you can do a crit every time you hit enemy, it just mean that your acc will just improve greatly than your reload (faster way to reach acc cap but you'll be having hard time to reach your reload cap)

ACC huge gunners for UK are not the better choice if you are looking ahead. Rld gunners will hit both caps earlier.