Is an ulnar nerve transposition effective for cubital tunnel syndrome?

Yes. Ulnar nerve transposition is equivalent to an ulnar nerve decompression operation for entrapment at the elbow.
Yes. very much so. I do it for recurrent cubital tunnel syndrome and for subluxation of the ulnar nerve over the medial epicondyle otherwise i do my release endoscopically.
Yes it is. When ulnar nerve transposition done the objective to release the nerve there , to avoid repeat of entrapment we do transfer the nerve.