Quick question. Why is the warlock charisma based? There is no in game explaination and I would like one as it seems to be more intelligence based, also what pathfinder deities work well and what ones don't?
There is a lot of interpretation involved in a warlock. Some like to interpret their magical powers as being directly dependent on an ongoing relationship with their patron, in the same way some like to view a cleric's spellcasting ability. If the deity or warlock patron wants to, they can simply remove the ability to use the magic, or in an even more extreme view, the deity/patron is the only one who really holds the power, and the magical act on the part of the cleric/warlock is just a request for the deity/patron to do something, which they may or may not decide to.
That view isn't really well supported by either the rules or the lore of the game.
The opposite approach is that once a warlock (or cleric) gains their magical powers, through some sort of arrangement with a patron or deity, or some other means, they
have those powers completely independently. If the patron or deity wants to take them away, they have to make active effort in some manner--just like they would have to use active effort to take the spellcasting abilities away from some random sorcerer or wizard or bard they wanted to punish for some reason. The most extreme version of this has them gaining their powers when they first gain the class, and then they can level up all the way to 20th with no further interaction from a patron or deity.
This view seems to me to have better support in more recent editions (I'm not a 4e fan, but it was explicitly true in 4e, and it's one of the things I like.)
There is then an entire spectrum of views in-between those extremes. (And 5e seems to be in the middle, leaning slightly towards the second view.)
If you choose to go with this second view, then Charisma has nothing to do with interacting with your patron. Instead, it has something to do with how you access your magic. The way I've described it is that a warlock doesn't learn how to cast their spells in scientific detail like a wizard--nor do they align themselves with a divine principle like clerics. Instead, they reach into the Weave grasp the spell they want, and
take it by their magic-infused force of personality (Cha), making it a part of themselves.