Starting RotRL, first AP, advice please

[Jiyva]

My 4 players are playing a Half-Elf Ninja, Human Ranger, Dwarf Fighter, and Elf Sage Sorcerer, all 20 point buy. The only thing that sticks out to me here is the lack of healing spells, but two of them have UMD so I'll likely give them some CLW wands. Is there anything else I should keep in mind running the AP for this party? The only other thing I can think of is the lack of Knowledge (Religion), which it seems might hinder the investigation in book 2.

[the David]

Well, the first thing that comes to mind is that all adventurepaths are actually written for a 15 pointbuy. So unless the players are inexperienced, refuse to play efficient characters, or enjoy playing on easy mode, you might want to change that.
Reading the entire AP before starting the campaign is adviced.

[Mudfoot]

The ranger can use CLW wands without UMD, so you needn't worry about hp healing. Status healing might be more of an issue, so drop in a couple of potions of Restoration and Remove X here and there.

The Misgivings could be tricky without a cleric (and with lots of sucky will saves). But otherwise I don't see any major issues.

[Fraust]

5 points of difference on point buy is no where near enough to change things into easy mode. If the players know what they're doing, it's going to be easy because the APs are written for the lowest common denominator, so to speak. 20 is just going to make some of the more MAD classes viable.

[wraithstrike]

Keep the 20 point buy and read the book before you try to GM it.

[bulbaquil]

Try to be as familiar as possible with Sandpoint in particular before starting out the AP - especially if your players are more roleplay-oriented than combat-oriented. You want to get the party invested in Sandpoint by whatever means possible - play to their character goals, classes, and playstyles to do this. (E.g. the Sczarni/Scarnetti "war" may be a good way to involve a rogue-type character, though it isn't played up much in the AP itself.)

Mechanically, will saves are likely to be a big issue as Mudfoot mentioned. You do have a sorcerer, so you'll at least have one "good will save" character, and in your case I'd be inclined to treat the haunts as fear effects that your fighter's Bravery will apply against. Maybe drop a headband of inspired wisdom shortly before you go to the Misgivings.