Lots of questions there.
I'll do my best.
I can't speak to the lawyer you found, nor would I. You'll have to shop around till you find one. Get a lawyer who doesn't play golf, doesn't wear expensive suits, and has a picture of his grandchild on his desk. It helps keep them honest if they think you're becoming a member of the community or if they think you have family in the area. The lawyer may charge you a straight fee or he may charge you by the hour. I like the straight fee. Be up front with the lawyer and tell him you're short on cash. This is not a lot of effort for him and he'll likely as not pawn it off on a legal secretary to prep the documents and such. He's done hundreds of these and it'll be almost cookie-cutter, minus whatever special considerations you put in.
You can start by asking the seller to pay for the surveyor. The lawyer will know a good surveyor or you can check the yellow pages. You want the survey and you may have to pay for it. The property I ended up buying for my homestead ended up 800 feet away from where the seller thought it was. In rural country, many deals are done on a handshake between community people but you're not part of their community. You may not be able to reconcile property disputes, easements, and other problems later on as easily. Particularly if you're not living on the property.
You'll have to pay someone to run a title search. It's sometimes called title insurance. You might be able to make the owner pay this. Again, the lawyer can handle most of those details and you'd bring the money to closing. When we did mine, the arrangement was that if the title wasn't clear then I wouldn't pay and the title research company would seek their payment from the owner.
I'll have to get back to you on the different parcels. That's not an off-the-cuff response.
Again, I'll repeat ... no road access, no deal. No contract stipulations, or easements. Let's say you make a contract with the owner now that gives you access over a piece of his property. Then he dies and his kid who lives in Salt Lake City sells the property to someone else completely. That guy puts up a fence and locks the gate on it which you don't find out until you show up in the rain at night with a carload of groceries. No road access, no deal. This is my advice. It might not matter so much right now if you're not living there, but if you ever have plans to, or think you might someday have to ... then best consider it now.
Call the county and ask questions to find out about the regulations. Start with the county clerk.
As for who pays whom and how much, the lawyer can help you negotiate out a contract that is binding. I would not go into an owner-financed deal that would take me more than 5 years to pay off. Much of rural America is being sold off by geriatrics whose children have run off to the city. The property to the east of me is owned by 9 different people, none of which have ever laid eyes on it. The property to the north of me is in tax foreclosure because the grandchild who inherited it is on welfare and can't afford to buy a loaf of bread, much less pay property taxes on 50 acres of mesquite scrub that her grandfather wanted her to have. Make a rock solid contract and then get it paid off and the title in your name as fast as possible.
As for a lawyer, call them. Go sit in their office. Stare at them menacingly across the desk and see if they piddle their carpet. This is largely a "vibe" thing. If you wouldn't buy a used car from him then don't hire him as your lawyer.
If something bad happens to you financially, healthwise, or spiritually then you may be 80% paid off and not able to come through with the final 20%. You may decide to cut your losses and lose the 80% but hang on to the 20%. The contract should be written so that if that decision is made then they can't come after you for the 20%.
If you're really good at real estate deals then you can use the agent listing the land. My technique has been to go to an area and find a real estate agent, then have him or her talk to the listed agent for any properties I find (or that they find). Once I pinpointed the area in which I wanted to live then it became a lot easier.
You're very welcome. I've only done this a couple of times and I've not had the experience of getting burned. Going into it thinking you're a moron is a great way to do it. If you go in thinking you're Donald Trump and that you eat land deals for breakfast then you'll get screwed over royally. Morons who know they are morons are way more cautious and cautious morons keep their money in their pocket.
Farming is hard. It's even harder if some grandchild, neighbor, or bank comes out of the woodwork on your tenth year and lets you know that they have an easement right through the middle of your hugelkulture beds and the bulldozer will be there that afternoon.