12 volts when I turn the key on, goes to 14 when I start the engine, but when I give it gas it goes down a bit . Is this normal?

its normal

when you turn on the key it shows what batt voltage is, when you start the engine its reading what the alternator is putting to the battery to bring it up to full charge, it will go down as the battery is recharged, have fun go boatin

How old is the belt. If its old for security I would change it. If it's newer I would just make sure its tight.

thanks!

listen to ws6

keep your old belt for a spare.