I guess I was saved from some of your sad experiences because I started so early; never submitted to LDS; and never put anything online.
I have had my research usurped but I gave it freely (snail mail.) I was just so happy to find someone else interested in my family. I was warned NOT to give away everything I knew. I ignored the warnings.
I have not been hurt badly and in general I doubt anyone was malicious.
Recall prior to 1900 most people spelled phonetically. I have surnames with many spellings. The key is to make certain they are the same people. I use the standardized spelling but always records Wills, Deeds, etc. exactly how they were written. Never change a 'primary source document.'
It sounds like you were burnt badly. I am very sorry.