The stake and grenades are in subweapon territory, so that'll be a no-go. As for the rest, Dwarmin's got the right of it. Your guys have unlimited storage space and pretty much no need of food or water - except for healing purposes, of course. Besides, turkey never goes bad, even when hidden in bricks and left inside a wall for who knows how long.
Anyway, about your exorcism skill, I have two ideas. Would making it so you can't Massively Fail attacks against ghosts be alright? (It would mean ghosts can't counter you if you rolled a 1 on your damage roll against them.) The other one is making it so they can't possess you. I'm going to ahead and run the turn, just let me know whether you want either of those or the +1 damage.
GENERALThe group heads to the general store to make some last minute preparations before they leave for the castle. When asked about grenades and stakes, the shopkeeper merely looks confused, but he does bring out the requested 10-foot pole for Wymar and the other supplies that Greenmoore asked for. "Will there be anything else?" he asks the group. (Giving everyone else a chance to request one or two items) Once their business was settled, the party set out for the eastern entrance. The time was almost noon when they saw the first bridge in the distance. Near it was a small shack, presumably used for toll-keepers.
(Wymar Sane gets: 10-foot pole!
Friar Greenmoore gets: A waterproof oil lamp, with extra oil!
Friar Greenmoore gets: Sturdy rope+grappling hook!
The salt and chalk won't really do anything mechanically speaking, but if you want to have them you can.)