I had a quick look through the forums and couldn't see an answer. If I have several of these scattered through my fleet, can I use them all on the same squadrons? Like, move my B Wings several times to get them to where they need to be?

I want to think they do, there's nothing that says they can't. It feels like a bit of a loophole, but most FFG games feel like that...

And I assume they synergise with Flight Commanders in that I can use the FCT and then the Flight Commanders?

Yup. Each triggers separately and all.

Hence the extraordinarily popular Nebulon B+ Flight Commander+ Fighter Coordination team+ Yavaris

Yes. Sounds broken, but try building a list around the idea and you'll see how balanced it actually is. The only there are currently four ships in the Rebel inventory that you can take it on.

CR90: squadron value of 1. Situational useful, but very little opportunity cost because who takes a support team on the CR90?

Nebulon: not a bad way to go, and of course it's amazing on Yavaris with Flight Commander. But if you're trying to stack them up, you're going to quickly run out of points FLYing 2 B-wings at a time, especially if you're also taking enough fighters/Intel to make those B-wings worth having in the first place.

MC80H: great way to push a full complement of B-wings all at once, but too expensive to stack up in multiples, especially, again, if you're taking a large enough squadron wrong to make sure those B-wings you've invested so much in get through. Also, the platform itself is slow, which doesn't seems like that much of a limitation, but does have tactical implications.

Liberty: squadron command is 2, really wants Engine Techs, and expensive platform means it's kind of a niche build, and, again, hard to stack them

This is all not to say that FCT is not good... it's just not as outrageously broken as it looks at first blush.

Pelta may make a good platform for them, but that will also suffer from the limitation of low speed.

No, they trigger and resolve separately.
You can resolve more than one, but you can't resolve two at once to move a ship distance 2.

Ard failed to mention YV666s, Interdictors, Glads and Arquitens!

Ard failed to mention YV666s, Interdictors, Glads and Arquitens!

Not important.