Keep the Bloodstones, even after it becomes inert, keep them all but dont use them all immediately you will need onefor a quest. Mini-spoiler follows....
(As Raze said use them in your inventory then pick it up off the ground once it becomes inert, it will give exp and heal you and unlock new doors in the homestead. You especially want to unlock Hall of secrets that is the 5th stone you find, the lady in there sells stat and skill books to improve your character every level up but they are expensive and in limited supply. You should have found 5 by the time you leave the Cyseal map providing you did everything and went everywhere.)
Heal potions never go above the Huge Potion level which heals 226 points I think, but all the other heals both water spells and cure wounds improve as you level up, eventually the AP cost to use the heal spells drops to like 4 AP, when your level in Hydro and MaA gets high enough.
I dont doubt the crossbow at all, they just dont really work that fast, I have one and have owned several and compound bows, composite bows, and a Longbow, crossbows should have a much lower dexterity requirement and a much higher AP cost to use, but should do more damage than any bow and should be more accurate, but that might be too unbalancing. A legendary one with Oath of Desecration, high user skill, leadership damage buff and upgraded with sextant , bowstring, and essence or tenebrium would be a freakin death ray!
