The card that received perhaps the most hype when spoilers for Kaladesh were first being released was Chandra, Torch of Defiance. And yet, that card has seen not much play. Now largely it was overhyped, but I still think the card is good. This deck started out as a way to try to maximize the card. To that end, you want a deck that can play for enough time to accrue advantage from the 'walker, and you want to have enough cards that are fine to good to play at sorcery speed (which means probably not a counterspell deck).
This led me to looking for lots of removal. And there's lots of removal in red and black, so here we are. Obviously there's some more nuance than that, but things aren't rocket science here.
There's plenty of removal here to be able to handle most of the aggressive decks, and they are of high enough quality to still be quite useful against the midrange decks. Control decks can be somewhat problematic, but your six main-deck planeswalkers do significant work here. Still, the biggest problems I find are with decks going 'over the top', since this deck doesn't really have a great way of locking up that endgame. Thus, the two biggest cards I've had problems with are things like Fevered Visions and Metallurgic Summonings. There's no way of dealing with these cards once they hit, and the deck doesn't have enough of a proactive gameplan to be great there.
I've tried a number of sideboard configurations, and I haven't found one I really feel is particularly great yet. 6 Mana Chandra has been a nice find, but of course you can run into a problem of too many Chandras. Liliana is good in some of the grindier matchups (like delirium) as well as decks with lots of X/1s, but you aren't running super many creatures, and you have ot think about how many you have post-board in those matchups. Gideon is a tough card for the deck to deal with, and that's what the Skysovereign is about, but I am not really convinced by it, especially in this deck. Incendiary Flow vs Harnessed Lightning is interesting - I've mostly given the nod to Flow because it's better against go over the top decks, Scrapheap Scrounger, Prized Amalgam, and planeswalkers, and you have a lot of instant speed removal anyway. But it's a real cost against vehicles and creatures lands (plus the increased flexibility of multiple HL).
The worst matchup for the deck is probably Aetherworks Marvel. It's just incredibly hard to win any time they find Marvel, which they usually will. If that deck gets popular again, this one needs to shift dramatically.
Finally, I'd like to note that the manabase isn't entirely clear - 18 black sources and 16 red is okay, but you have a reasonable number of tap-lands, you get no creature lands, and you could use a little more in terms of sources, and maybe even slightly more in terms of total land count.
Overall, I think the deck is pretty good and pretty well positioned, but
it needs some tuning - slightly better proactive plan probably, and
better plan against 'walkers like Gideon. Maybe some of the Unlicensed
Disintegration should turn into Ruinous path? At which point maybe you switch some Flow back to Harnessed Lightning.