1983 Carver 32

Zack, there is no "normal" when it comes to a boat.

Where did you notice the gas fumes? If it was in the engine room it could mean one or both of the engines might need a tune up or at least new plugs.

If you are smelling it outside around the exhaust it means the fuel is not being completely burned...again tune-up.

As to the price, look around at other Carvers in similar shape and year. From my perspective, Canada, I think if the boat is in good condition, $18,000 is not too much,, but always, always offer less and see how badly the owner wants to sell.

I bought a boat for less than half the asking price because the owner just wanted it off his hands.

And if you need the bottom sand/soda blasted and re-painted expect to spend around $5,000

Welcome to YF Zack. Let me try to address the points you raised.
As for Carver love/hate, Carver are notorious for having a lot of space and amenities, but they're not the most seaworthy boats. So it all depends what you plan to do with it. I suspect that on a lake and living aboard you won't find yourself in seas it can't handle. One thing I'd be concerned with on a Carver that age is the balsa cored decks. Walk all around and feel for any spongy areas.
I suspect that the motors have been rebuilt a time or two. Do you know how many hours are on them? A good rule of thumb might be to figure 1500 hours on a gas motor before rebuild, and about $8,000 to 12,000 for the rebuild although it could be far less depending on how extensive.
Bottom painting you'll do every year or two, and change the zincs every year. If you're moving it to a fresh water lake you'll want to change the zincs over to magnesiums.
Have a marine mechanic check over the motors and in particular have him do a compression test on them. The broker moving the throttles before starting tells me that they're carburated motors. That also explains the smell of gas. Too many people pump the throttles on carburated motors. They develope a memory and soon need it. Ideally you want to pump the throttle about once at most. Better though simply advance the throttle as you're turning the key until she turns over. You may be stuck with this situation though at this point and age.
Sure gas is less efficient and more expensive, but I suspect if you're on a lake it'll be much easier to find than diesel. So no worries there.
Some gens start easier than other, but it may just be because he didn't hold the pre-heater on long enough.
The price seems fair, and a good price for your first boat. You'll probably find this boat to be a good learning experience without laying out a ton of cash.
I generally strongly recommend having a boat surveyed before purchase, but in this case and at this price I be more inclined to recommend that you have a marine mechanic check the motors & gen, sea trial (and check the bilge for water intrusion and leaks as you do), and turn on all equipment to see that it's in working order.
Understand going in that this is not a good financial move. Buying a house would be far better. But it will be a great adventure for you and your GF. Enjoy and good luck.
P.S. Believe nothing the broker tells you. Check everything for yourself.

You didn't mention the battery charger. Check that also. I DK much about ham radio systems, but a friend had one on his 26' Sea Ray, so I assume you're ok. Check the amperage draw. You should have twin 30 amp shore power. One side will be for your air conditioning and the other side for everything else. Managing load is always a concern as you add things not designed for boats. Another thing to consider is that those radios are not marinized and the marine environment is corrosive(damp). Keep them in a dry location.

One other thing to give serious consideration to is the appliances and closet space. You probably won't find better on a boat that size, but the boat is considered more of a weekender than a live-aboard. Have your GF take a close look at those things while considering her lifestyle. (Women think differently than us about creature comforts).