TBH I would remove missiles and torps on the cruiser. The destroyer is also supposed to be anti-bomber so its ok if it keeps them.
A change in the economy would also be a great help to the interceptor, a change that included a flat reward for kills in addition to a reduction to the current ship price based reward. One of the interceptor’s biggest weaknesses is that it can’t earn credits like the other ships can. Sure you might get 2-3x the number of kills as a bomber, but 1 kill in a bomber is worth 300 or so credits while one kill in an interceptor is worth 20-80 credits.
While we are on the topic of interceptors, one thing that the interceptor lacks is any ability to stop hit and run attacks, ie warping in and torping a station turret and then warping out. By the time the interceptor has gotten to the bomber the bomber is already gone.
If the bomber builds up speed, it is basically guaranteed an escape from any interceptor as by the time the interceptor builds up the same speed, the bomber is well out of missile and gun range and able to warp. If the interceptor tries to catch up to a speeding bomber via warp, it can but will immediately fall behind the bomber when dropping on it.
All in all, a smart bomber can get in, drop its payload, and get out before even several interceptors can do anything about it. Only time an interceptor has a use against a bomber is when the bomber is using his shotguns, but at those ranges PD will a single bomber before it can do anything.
If you really want to make the interceptor strong against bombers (leaving the destroyer to be a general purpose anti-strike craft (vette, bomber and interceptor) with some anti-cap ability), you need to give it some long range “interception” abilities, so it can take out bombers before or after they start their bombing runs. Something like missiles that can travel really fast, deal no damage, and knock players out of warp before they are within 60 km (optimal LR bombing range) of their target, an ability to drop on a target and match its velocity from warp (thus defeating the use of high speed to escape) and maybe even a flak cannon to shoot down torps and mines with as well.
Perhaps I am going too far with the long range interception ideas, and the issues I am seeing are more a lack of fleet composition than interceptors lacking ability, but as I see it unless you have a fleet to support you (ie multiple vettes/destroyers for warp jam scattered about) a single interceptor struggles to shut down a single bomber if the bomber is content with hit and run as opposed to close in fighting.