Agree with almost everything here
I have never understood contrived nicknames, or when you want to use a particular nickname and then try to find a full name to match it. Cameron nn Ron doesn't make sense at all to me, and if he always goes by Ron, there's a 99% chance people will assume his name is Ronald. Like mirfak said, the -ron is not even stressed in the same way.
I agree about the syllable stress nicknames being fine, but I still don't understand how a few common nicknames come about. Robert nn Bob, and Eleanor nn Nell still confuse me. :) I'm one to shorten a name based on stress and the letters present.
Only one name on my entire list has a nickname that I might use (Anneliese nn Liesel). And I like fairly long names! I think it's because I grew up with a fairly long name (Catherine) and it never got shortened and I hate all the usual nicknames for it (except Cate, but I am never called that). I think the full names are beautiful by themselves, and nicknames sort of ruin the beauty for me. (Margaret nn Maggie is an example: it rhymes with "saggy"!)