Mostly need the MSQ pot really to skip ARR if you've done it already. Leveling is actually pretty fast, don't know the situation on the server you picked or if there's still any left for the US datacenters but they have Preferred servers you can pick(list is on the Lodestone webpage) that give double xp until 60 to everything(even crafting/gathering) and that doubles other normal ingame bonuses, so shit goes really fast, plus you also get some gold and some subtime(15days) if you reach lvl 30 if that's still going.
But running leveling roulette+dungeons/PotD/squad missions with the first time GC log bonuses and shit like that, I'd expect it takes maybe 10-12hours of gameplay to get to 50, which is fairly reasonable. At that point you can unlock every classes too if you planned on playing one that's not available at the start, the HW one will require relvling but the SB ones would unlock at 50 right away.
Also you have to buy Stormblood only. They do it differently than Blizzard which has all expansions but the last one rolled into the base game, probably because it's still early and they only have 2 expansions, but buying SB gives you HW too. There's sales all the damn time for SB too. That or if you're starting fresh, you can buy the complete edition which has base game+expansions.
Couldn't you just play your old account though? Saves you some leveling/questing, just need the expansion, can just pick another class if you want to restart.
