Even if you save 2800 dip with influence, it just refunds your group. You didn't actually gain something out of it, like you would if you picked another idea group that would have snowballed (dip, adm, even religious, huma, etc.). So yeah, influence without heavy vassal play => crap group. It's made that way.
Espionnage is very meh as well, you get claims on everyone and their mother with your MT anyway, so you're just using this as a -20% AE. And in that department, Dip offers similar benefits (BROT) with the added WS% (absolutely amazing when you want to WC) and tech up for binging up dip tech after having dev pushed for institutions. There may be situations where you'd want it, but this is not one of them.
Flipping ortho religious diplo and admin (in whichever order, not offensive lol) is a viable strategy, but you fight rebels forever, you need to eat some corruption, you spend a lot of ducats converting, you lose ottomans government, so arguably it's amongst the worst way to use the Ottomans towards a WC. At least this patch.
Exploration is just a waste of points
Aristocratic (or any mil idea group…) shouldn't be considered even in your first 3 idea groups. These are the ones that helps you snowball, you should be able to win over AI anyhow if you want to go for a WC.
Inno is an interesting one imo. There are some really nice parts to it, but it has some heavy drawbacks: first, it delays your rebel combatting idea group (huma if you stay sunni, religious if you choose to do a discount byz run) so you will fight the zombies for longer, which is tedious, and you will gain more AE out of not having yet the correct idea groups. Then, it delays your first mil group (possibly 4, becomes 5 or even 6), which means you need to micro more, pay more attention and it's tedious as well. So, the perks are nice, you get good institutions, good policies, you shouldn't run out of adm later on if you picked this group but you really pay the price in the early to mid game. Would not recommend.