Great guide, goes far beyond what previous ones have offered. Since you go into detail and cover things other guides haven't, I'll add a few things you didn't mention that are part of my experience playing Bowser:
-utilt now chains into itself, you can spam it, hit the first, have them airdodge the 2nd and hit the third. A character with lower airspeed like Little Mac is pretty helpless in this situation.
-The famous "Bowser bomb between Sheik's ftilts" only works at percentages low enough to not take you off the ground. A good Sheik never really gives you the opportunity to use this OOS, ftilt usually comes while you're in the air already because of a throw/fair. It's worth mentioning, but I would be surprised if any tournament Bowser player has successfully done it.
-I'd add Rosalina as a Bowser bomb to ledge exception, her uair disjoint will always hit Bowser out of the move. Unfortunate as Bowser is completely outclassed offstage by her already.
-Regarding ftilt, I'd like to see a warning about using it too much in the neutral. It may be safe on shield, but it is not safe on whiff. I've caught many a smash that wouldn't have hit me by trying to poke with ftilt and having them hit Bowser's extended fist.
-On tough guy, it may go beyond the scope of your guide but there are so few characters the move works in our favor for that it might be worth mentioning we can tough guy through Little Mac and Sheik's jabs, and Ness' PK fire at low percents.
-Flying slam has a problem you didn't mention, it whiffs if the opponent is too close (along with ftilt, though that is less of a problem). If they are partially inside Bowser, it's not the move to use. It's possible to accidentally whiff against a stationary opponent if one takes this for granted.
-You briefly mention the problem of Bowser's aerial fortress not snapping to the ledge when his back is to the stage, but don't mention the solution - use klaw to turn back around before getting back. Certain characters' downthrows (Sonic, Toon Link, probably others) will always put your back to the stage, and in those situations it's really better to turn around so you don't get punished at the ledge. But we shouldn't impatiently mash side b while still in hitstun, that will result in sending us further out.
-Sorry if I missed it, but something that I've gotten good mileage out of after hitting an opponent offstage is hanging on the ledge and timing a drop-off bair when they recover low. Not saying it's the best or worst option, but it is an option.
-Ledge trumping could have a little more time given to the mechanics of it. It's legitimately difficult to do with Bowser compared to many other characters so any explanation of what works most consistently for you or the alternatives might be helpful.
These are all kind of picky things and you're not obliged to add any of them, but some might find some of them useful to know.
