Swagic, there's a little bit of misinformation in that post, but most of it is good. When yoshi's super armor "breaks," he's still in fall animation - he doesn't really get sent anywhere, he just stops jumping, he can air dodge, nair, etc. Fair is decent as always, but at the higher % (which is when you're most likely to be edge guarding), I'm talking 75-ish +, I'd really recommend doing the reverse up air. As taukhan mentioned, strongest hit of up air breaks at 54%, so probably the reverse strong hit will be something like 65% (total guesswork though), and then before he can even do anything else, he's falling right alongside you at which point, you can up air again. IMO it's definitely a better option. Guaranteed death as opposed to breaking armor and hoping to hit him again.
But, if at around 30%, you should go for fair, it just likely won't be an edgeguard scenario is the only thing.
FD is actually really bad for yoshi, from what I've been told. A lot of his movement relies on platforms - just watch aMSa play, he wavelands all over those things, dare I say it, more than a ganon does. Eggs aren't really that much of a problem for ganon at all unless you're getting edge guarded or he's trying to hit you on the way down after a juggle (which also isn't that bad, as it isn't a setup in that case, just extra percent).
You're right about a grounded yoshi. Basically the same as with any opponent, if you think they're going to shield, tomahawk grab can beat it (assuming they're parrying the aerial and not the grab).
Yoshi's approaches are all gimmicks basically IMO. It's mostly tricky waveland DJC stuff that messes with your spacing. Give him a little more space than you'd normally anticipate and walling with bairs / tilts is always really good (as always).
When you get eaten by the tongue, it's kind of an even trade if yoshi decides to go for the dair lol just hold down and mash the a button and you'll stomp him. Actually works pretty much 100% of the time after yoshi dair.
Optimal play, ganon wins at least 60-40 IMO.
edit: what I said about the super armor may not actually be true for stomp - stomp may or may not actually fully break it and meteor spike him.