1. The current owner does not have title insurance on either property. Do you think this will be an issue at all considering that I do plan on getting title insurance? You do not need a prior title policy to get a new title policy but it does mean you will need to do a longer search (typically at 30 years back) because you cannot "tack" onto the prior policy (which allows a search forward from the date of the prior policy.)
2. I want to be able to sell these lots to someone who plans to build on them so I went to view these properties myself. One of them has quite a slope but it looks possible to build on it in my (unprofessional) opinion. There were some trees but no huge trees that would hard to remove. Adjacent to the lot I plan to buy there was a neighbor who built a house and the slope on their land is similar. I checked the zoning so I know you are allowed to build on it. Do you think I should get a professional opinion from a builder before closing the deal? Yes - if you intend to build make sure that is a viable option before you close.
3. How long of an "inspection period" is reasonable. If I plan to close in three weeks can I make the inspection period three weeks long up until the day of closing? It is negotiable. The longer the better for you as buyer.
4. Is there anything else I need to do myself? Land survey, ect? As a general rule, I would recommended a survey.