Serger's comments are generally correct except where noted by previous discussion (mainly the large AMM sensor is fine due to missile tracking tech, though you should really research better sensor tech!). The range is indeed very long and could stand to be reduced either by reducing fuel by 1/3 or 1/2 and/or increasing the EP boost. Even 15b or 20b km range gives sufficient strategic mobility on the defensive as you are mostly making one-way trips and refueling at bases or from tankers, rather than striking into enemy territory which requires more endurance.
While other comments are correct about ship size, to me it is also an RP consideration so I would not worry too much about it although the points made are absolutely correct.
Following on the BFC discussion, If you set the range to 48,000 or 64,000 km you will greatly improve your PD efficiency, which can let you reduce the load of Gauss turrets. Most straightforward would be to keep the twin 2x3 setup but reduce to only 2x turrets, which would also allow you to use 2x SW fire controls instead of 1x MW for a bit of redundancy - the cost is the same, and the RP investment is a few points less.
With the space saved, you must increase the missile salvo size, not warhead. size-4 WH-4 is a reasonable missile design depending on tech level (if you have rushed the 8k RP techs then WH-5 is perhaps more efficient, even WH-6 given the high speed you are currently deploying). However with box launchers the goal is to have an overwhelming volley size to make best use of the small component size, and by removing two Gauss turrets you will gain over 20 HS in space very easily which can be used to multiply your box launcher load by a factor of 4 (from 12 to ~48 or so). This brings your volley damage with the current missiles up to a far more intimidating 192 per frigate which would be easily enough to destroy a similar opponent - of course after AMMs and PD the picture will be less favorable but against NPRs such a tactic is very effective.
I would also cut the size of the MFC by 50% but have 2-4 of them depending how much you want to be able to split salvos (not only against multiple targets, but this can also reduce enemy PD efficiency somewhat with small enough salvo sizes). This will cut MFC range by ~30%, which is fine - your MFC should not outrange your active sensor, rather the reverse should be true as this allows you to maintain a target lock while retreating after a volley.
Also, remove the Main Engineering module. It is usually difficult to find enough Engineering-skilled officers to staff these, so they should be reserved for capital or large command ships. Bridge + Aux Control is sufficient for a 9,000-ton patrol or escort class, and if you needed a third module the CIC would be a better option as there are plenty of junior officers with a Tactical bonus. Otherwise, as a CIC is 10k RP you can put some passive sensors as Jorgen recommends.
On a side note, some time ago experiments were done finding that for Gauss cannons, the 1 HS size is actually most efficient for PD due to salvo overkill effects. This is a relatively minor effect but it is worth noting particularly if you face significant AMM spam from the NPRs. No change is necessary as any size of Gauss gun will work fine, but a smaller gun does reduce your RP investment somewhat especially since you must research twice (gun, then turret). I usually use the 1 HS size for this reason as well as the 1-HTK statistic of the weapon.