Union or not, management will crap on you. Just because you vote in a union, doesn't mean the grass will grow greener, rainbows apear and the birds sing.
Of course not, but you have a binding contract and a legal recourse when they try to sh*& on you. The work rule reductions that Skywest management has taken over the past few years, not to mention the elimination of COLA, would not have been possible with a union. Unions don't wave a magic wand and make everything instantly better. But, they do provide a legal framework for you to work towards making things better, and they provide the resources to make it happen.