Please forgive the total newb questions I'm about to ask.   ;D

I want to customize some baits with paint, glitter, and/or any other ideas you all may have.

I was wondering if I add paint or glitter to a crankbait, will it change the way it balances, floats, swims??

Also, I want to paint some spinnerbait blades and I'm looking for a clear finish I can put on to protect the paint, and maybe also put right on over the plain metal to protect the shine and keep them from tarnishing on blades I don't paint.  Is there something that I can buy at the local home center that will do this??  Right now I picked up a can of Valspar clear enamel spray that says it's water resistant.  Is this good enough??

Most crankbait painters shoot water based acrylic paints though an airbrush, then clear coat the bait with a waterproof durable topcoat like epoxy, a moisture cured polyurethane, or an auto clear coat.  If you are "just messing around" and adding a few accents, a colored Sharpie pen gets the job done quick, easy, and cheap - but will eventually fade.  Glitter is sold as a powder to mix into a clear topcoat or ready-mixed as paint-on glitter in a water based acrylic clear.  You can mix powdered glitter into a clear nail polish for a "fast fix".  Nail polish will also protect sb blades but be aware that it also makes them heavier and harder to get spinning.

Anything water based you put on a bait has to be coated with a waterproof topcoat for it to last, and there aren't many good "go to the store" choices - none I know that are anywhere near as durable or waterproof as the special topcoats used by bait makers.  Try the Valspar but don't expect it to last as forever.  Don't try shooting an enamel product over a different type of fresh solvent based paint.  That's often a recipe for bubbling and extreme failure of the finish.  If you want to use aerosol rattle cans, stick with enamel over enamel, etc.

Regarding performance, a new finish adds .02-.03 oz to the weight of a bass crankbait and it's distributed uniformly over the bait's surface so that the impact is negligible.  That said, ANYTHING you do to a crankbait will change its performance to SOME degree.  JMHO, if it catches fish great now, leave well enough alone and thank the tackle gods for bestowing that gift on you, however temporary the gift will be.