As you have agreed upon all of the costs, put everything into a lease calculator and make sure your payments are that number when you're signing your deal. If they add extra fees, tell them you did not agree on the fees - you should be at a point where your sale figures are finalized. Our CA brought up the MACO fees when we were doing the original negotiation.
1. When you're working with the finance person, they will try to sell you extras (i.e. clear bra, tire insurance, leather protector, etc). If you search here, you will find threads on all these with great input.
2. Gap insurance is included in the lease payment
3. See first paragraph
4. We did not have to put a security deposit down (or down payment) with our first BMW lease. We do have great credit and a car buying history, but if they tell you that you HAVE to, you should be able to negotiate that as well. You should be able to lump that all in your cap cost, but probably don't want to because you end up paying interest on it. See if they can waive the deposit and use that to pay your fees.
Hope that helps