Ok, let´s have a look
For ICF drives, they are quite slow. Not as big a problem with missile ships, as they are supposed to have the range to touch someone but it still might be an issue.
They have quite heavy armor for the size (those would be DDs/DDLs in my games and tincans don´t get a lot of armor in my book)
They also have a whole lot of maintenance parts. Could easily get away with half of it, given you have fuel for less than a year (yes, they will probably sit most of the time in orbit somewhere, but then there should be maintenance facilities, where they sit, so they won´t add time on their maint-clock).
The escort cruiser looks ok-ish.
The range of the res-1 active against size-6 and smaller missile should be around 1 mkm which is rather short, but it is in-line with the range of your AMMs. Personally, I like to engage hostile missiles somewhat farther out.
The missile cruiser looks good.
Given the size, 8 x size-5 launchers is quite good. Don´t let yourself being talked into bigger ones
Yes, large missiles pack a bigger punch, but each missile shot down by PD is a lot less damage dealt. Personally, I am in the "missile spam" camp. Size-4 and lots of ´em -- blot out the sun kind of lots.
I also avoid using several different missiles of the same size on one ship - or at all - simply for logistics reasons. It is a PITA to keep the battlefleets supplied with missiles as it is, no need to further complicate things. Also, if I have a long-range shipkiller, I intend to use it and stay out of the range of counterfire. Yes, there will be times, a short-ranged, heavy hitting missile might come in handy, but is it realy worth the trouble?
In addition, I can already hear your captains screaming in rage, when they have pounded the enemy´s shields down from long range and finally start to punch some holes in their enemy ships only to be told that the long-range stuff is all out any you have to close to short range to finish the job. Which will take half an hour and allow the enemy to recharge their ships _and_ blast away at you while closing.