Welcome to Fluther.
Is the boat tied to a dock or swinging on a mooring? If it’s tied to a mooring, then when was the whole anchor system last inspected? Would you be responsible for storm preparation? (And can you be? Don’t forget that the Atlantic hurricane season runs into November.) If it’s tied to a mooring, then don’t forget that you have to get to and from the boat in all kinds of weather and all kinds of conditions, and sometimes at night.
What about the marina access and parking (assuming that the boat is tied to a dock in a marina)? How is the security there? What are the neighbors like? Is it a noisy area? How well protected from rough weather is the anchorage? When was the last time that an evacuation was required due to extreme weather?
Who will take care of the dockage fees, power, and sewage disposal? I’m going to presume that it has propane for space heating and cooking; you should check that out. Be aware that propane is heavier than air, so if there are any leaks to the system below deck, that gas will accumulate and could become explosive.
Finally, and perhaps most important of all: What kind of condition is the boat in? How is its fire protection? What about the condition of other boats nearby?