They have no connection to the Horde whatsoever. Not even in their previous iteration as extradimensional creatures.
yes they did, Ralaar the alpha prime made an alliegance with the forsaken in order to obtain the Scythe of Elune in Gilneas. There are technically two worgen factions, Alpha Primes army who's intention is to wipe out Malfurion and his children, and then the gilnean worgen which were cured of their madness however still cursed with the form.
That's interesting and could have been a possible avenue for them to enter the Horde, but I think the Gilnean worgen were the ones in mind.
Orcs wouldn't be happy their mounts are more intelligent than them.
1) Load the amount of weight I would deadlift onto the bench
3) Crank out 15 reps
4) Be ashamed of constantly skipping leg day