Mostly reading, but I just wanted to say a few things.
1) If only Spammerer still played.
2)
[MK] (arguably) invalidates DDD, ROB, Marth, Olimar, DK, Lucario, .
I lol'd.
3) John, is your question, "How does MK lose on non-FD neutrals?"
(i'm going to be talking from the Diddy vs. MK perspective)
What is it about platforms that gives MK a huge advantage? People seem to have this conception and I don't really understand it. Just because BF has platforms doesn't mean Diddy's (or I guess anyone) vs. MK is helpless or whatever. Diddy has a lot of dumb gimmicky tricks on Battlefield. The platforms are at an ideal height for him for various things (I could list them if you want), but in general I don't see the match-up changing much in MKs favor because Battlefield has platforms.
Diddy can infinite MK on FD rofl.
MK is REALLY DUMB on SV, and it's weird because people complain about scrooging yet take him there anyway. The moving platform = scrooging + giving him more safety in general. If I'm playing someone who I know won't play like that, I won't strike SV, but if you're going to be perfectly safe I'm not sure why you wouldn't. I also strike PS1 because matches tend to be campier there, and I'm more worried about getting timed out.
Not sure about the other match-ups/characters though.