I thought an LLP must be set up with a view to making a profit and that rules it out for a syndicate.
Basically, a limited company protects the other members from the actions of the member who was flying.
It does nothing to protect the pilot. AIUI. He will always be liable for damage. If he is the owner, he will be strictly liable for ground damage (though this is historically extremely rare) but he is liable to passengers only if negligence can be nailed on him. Maybe there is a way in which a ltd co. might protect the pilot at the time? I can't see it.
I had a big run-in with the Revenue over BIK and apart from learning that they are a bunch of crooks who randomly attack anybody who they think they can get a cheque out of, it transpired that if all pilots are part-owners (of the ltd co.) then BIK does not arise.