I know these builds aren't optimised but they do work, as to the swarm I just ignore it, I tried several gauss cannon builds (an FDS build cooked itself! LOL) but the shotgun effect of the shards means I can just manually aim at the heart without having to faff around targeting it.
I almost never subtarget hearts, they glow just fine for aiming gauss cannons at them. The only exceptions so far are hydra (where the glow is much less obvious) and when I killed a basilisk using only AX MCs. Again, shards are fine for cyclops, but for anything bigger you really want gauss cannons unless you are intentionally handicapping yourself for a challenge. When you are trying to kill a new interceptor variant, that in itself is usually challenge enough. Gauss cannons are also fixed and only small ones have micro-gimbal so subtargeting does not actually help that much.
Shards have their niche use though, I did use two shards during the AXI Ceres Trial season 2 because they are superior against the shield.
You also cannot just ignore the swarm for an extended period of time for higher interceptor variants (you need to kill it or avoid it) as it is sure to come back to bite you.
I try and keep combat straightforward so I don't bother with the heatsink tactics (doesn't seem sporting you know
)
Try killing harder interceptor variants without heatsinks and they will roast you. The heatsinks have double purpose, they both mean you can cold orbit and you also do not cook yourself.
TLDR; If you are happy clubbing cyclopes, you can use almost whatever build and tactic you like as they essentially die when you sneeze at them. Once you go to more difficult variants, this will no longer be true.