Thomas and John could be brothers of William. I don’t have anything on either one of them.
The burial for Ann Kelly German 11 Feb 1864 age 69 could be right. Your Ann should have been 67 but that may be close enough for their “flexible” math.
1861 census—I used Brian Lawson’s index and that is district 2 entry 90.
Shen Valla—try Frances’ Manx Notebook
Quanes—I don’t think the Quanes are limited to Patrick. I’ve seen entries for a number of other Parishes. Ann’s residence at marriage isn’t necessarily her birthplace. She could have been there working?
It takes being “a dog with a bone” to get anywhere in genealogy. GOOD FOR YOU!
Keep me posted.