Sounds like a good plan and unless there is a need for full automatic transfer I wouldn't worry about it for now. Since we retired I like the full automatic but ours runs on natural gas and we are sometimes gone for weeks during the bitter winters. That's when stuff starts freezing and bursting. Fortunately we are also blessed with some great neighbors which helps. 
Overall your project is really going well. That does suck about the relay and you needing to "fix" a new out of the box part. As to things like the ventilation most of that has been purely a learning curve but you have been doing great.
Before I forget and I may have mentioned this earlier, depending on your winters you may want to consider an engine warmer like a heating oil dipstick so if you need the generator in the winter you get an easy start.
Ron
Overall your project is really going well. That does suck about the relay and you needing to "fix" a new out of the box part. As to things like the ventilation most of that has been purely a learning curve but you have been doing great.
Before I forget and I may have mentioned this earlier, depending on your winters you may want to consider an engine warmer like a heating oil dipstick so if you need the generator in the winter you get an easy start.
Ron




