So if you were a Corvan anti-fighter escort frigate about 100 metres long equipped with quad lasers. How many guns would you have ?

At a wild guess, I'd expect it to be able to match the firepower of a Corvette, but with a focus on point defense rather than engaging large targets at long range - laser cannons instead of turbolasers?

If they are in turrets you could go with the "B-17" or "B-29" style. Nose x1, Dorsal x2, Ventral x2, Tail x1. In Huge game terms it probably means 2 Hardpoints and a primary turret. As at 100m it is just about the size of the transport it probably will only have 1 section, whereas the Corvette at 150m has two sections.

The primary turret could be given the quad laser range limits.

Agreed. Make the main armament a range 1-3 (or range 1-4) rather than 3-5, and allow it to spend energy to make multiple attacks rather than add attack dice - or better yet, to reduce opponent's defence dice (since that explicitely helps against fighters and not against capital ships).

The secondary weapons will be hardpoints, so....well...frankly people will put what they like bolted on. But you'd supply it with quad laser cards by default. Or even a "Corvan Only" hardpoint called something like a "flak turret".

So if you were a Corvan anti-fighter escort frigate about 100 metres long equipped with quad lasers. How many guns would you have ?

Well, that depends on the maximum effective range of the weapons. You would want to triangulate the batteries so that they have interlocking sectors of fire, then space them accordingly.

give it cloaking ability...lol

Four