Thermal penetrates shields better. Kinetic does better against hull. It's always better to use both.
This has been the case since the game launched. Thermal does better against shields every time.
I personally go cannons over multicanons though. And beam laser over pulse laser
This. Although IMO the huge MC is a big step up from the Huge Cannon.
Pulse lasers are so 2.0. Pulses have the advantage of being the best bang per MW of energy, which was great PvE meta when the AI was dumb as a brick and would sit all day in your crosshairs.
Now, the AI flies a lot better and burst damage is a lot more important. For lasers, beams currently rule the day. If beams aren't your style, go burst laser. Burst lasers have the best bang per buck against hulls (it's a hidden statistic, and it was valid in 2.0. Haven't tried it in 2.1 as I use beam laser/kinetic combos for combat).