No credit card required
Browse credit cards from a variety of issuers to see if there's a better card for you.
No, it won't hurt you. You'll just have a $2 credit next statement.
It won't hurt anything or help any extra above and beyond $0. It'll report as $0.
For max points, pay all CCs to $0 except one and get one to report a balance of under 9% of the CL. IMO, util isn't too important until you app for something. While keeping higher balances over time is bad in the eyes of creditors, just make sure util gets in check before apping for anything. FICO has no memory of util.
For max points, under 9% [for your one CC]. YMMV on that level. It might be 1%, 2%, 5%, etc. You'll have to tinker with it, but at that point you're only micromanaging a point here or there.