500 provinces and 100% religious unity.
For the start, what I usually do:
Before unpausing kiss up to the Mamluks to get a RM and alliance (they'll turn domineering towards you early, but good relations will change them to friendly/cordial). Rival Haasa and immediately declare war (take the stab hit. check if you get a mission before declaring war to take them over for a free CB to avoid stab hit).
What Haasa does now dictates how you proceed. Sometimes they won't get any allies. Good, just take them over. Sometimes they will ally QQ and pull them into the war. You might want to restart as you probably won't be able to take on QQ. Sometimes they will ally Oman and pull them into the war. This isn't bad. With many loans and mercenaries you should be able to beat them both and get Oman as a vassal as well as Haasa. I haven't seen Haasa ally with Yemen or Hedjaz.
Afterwards start fabricating claims on Hedjaz and Yemen (and Oman if they're not yours yet). They will eventually go to war against each other. Tackle the weakest and vassalize them (you might want to wait for them to finish their war so you don't get dragged into their other war, though if their other enemy is weakened too you can keep going). Once you have the hole arabian peninsula as vassals, Mamluks as ally, and probably also Ottomans as ally (this is a strain on diplo points, I know), start working your way up through the hordes towards Muscovy. You want to block them off. This might be tough if Lithuania decides to turn Golden Horde into a Protectorate.
For QQ you can take some Iraqi provinces (and Persian ones if possible) and release them as vassals. Then feed them the rest of the Iraqi provinces before you annex Iraq. You can keep Persia when you tackle the Timurids to feed them all those Persian provinces.