Congratulations on your new baby! Quakers are wonderful. They are definitely full of spunk. It sounds like Delta is doing great!
My Sammy is a bowl dumper too. If his bowls are not secure, he will toss them. The suggested Lixit bowls work great to prevent this. Sam loves the clear colored ones. His favorite is the neon green one (he hijacked it from the budgies). He likes to undo knots as well and take things apart. I take Polly Rope and tie it to his cage with a small foot toy. He enjoys untying the rope and then tossing the toy on the ground for me to pick up. Don't forget while looking for toys to get some weaving material. Straws, dowels, Popsicle sticks, leather strips, all quaker favorites for weaving.
As for bathing, like what Sandra said, I'd let him try to bathe in a glass pie pan or something similar. If you do decide to spray, show him the bottle first and what it does. It may lessen the shock of realizing that water comes out of the thing. Sam is terrified of spray bottles, probably because I as a beginner bird mom didn't do that.