Overall it is a good idea to do the FSBO route if you have found a buyer. Typically around here the seller pays 3% of the sales price to the buyer's agent (if there is one) and 3% of the sales price to the seller's agent. Do the math on your selling price and you'll see that it can be a lot of money.
I've only dealt with real estate in and around Boise, Idaho, and local purchase and sales agreements and customs and practices vary from region to region from what I understand. That having been said, here are my answers to your questions as things would work in Boise:
1. The contract can be boilerplate. As the seller, you can probably get some from your local FSBO office or from a friend in the real estate business. Around here they are three part carbon things, but you could print off a copy from the internet. What we did is get together at a coffee shop with the buyer and fill it out together. That is faster and easier than offers and counteroffers and counter-counteroffers. The buyer's mortgage broker doesn't care about the contract much; they mainly are interested that the house appraises for at least the selling price.
2. Both parties can and should work with the title company. Just call them and talk with the title agent and see that they get what they need. Anything to do with the mortgage loan is on the buyer to take care of; all you should care about is that the buyer is being diligent in acquiring financing, but if you want to help him with that it'd be nice and may create goodwill if there's something else you want as part of the deal (like a different closing date, or something).
3. On the boilerplate purchase and sales agreement forms here, there is a grid listing all of the typical closing cost items, with spots to mark for "Seller pays", "Buyer pays", and "split equally". There are items that are traditionally paid for by the seller, and others are paid for by the buyer. But, it is really just adjusting how much you and the seller walk away with, so it really doesn't matter except for that. The title company will just get all the numbers and follow whatever is in the purchase agreement.
4. You certainly could. I wouldn't, but that's because after having bought four houses and sold three, I know what's going on and I'd rather help the buyer than pay a realtor 3% to get involved. Also, to me there are disadvantages of a realtor - they have their own interests in the deal, they become a communication barrier and time sink between you and the buyer, etc. Buyers, especially first time buyers, are often cash-strapped, so if you ask him to pay 3% of the deal to his buyer's agent, he might stiffen up and want you to pay more of the closing costs, or have a lower price, or something similar - which would have the effect that you would be being asked to contribute something to pay for the realtor. Up to you if the dollar amount is worth it.