Seller financing on undeveloped land

[Chidera Ezeigwe]

I have recently come across some undeveloped land that I would like to purchase. Seller is offering 5% interest only financing with a balloon payment at the end of 3 years with ~1/3 of purchase price down. I would like to go in on this deal as it seems quite good. But just wondering if there are any pitfalls to look out for. 

Also, plan is to subdivide the land and build. Will I be able to do this while still under financing? Is there any risk to this? 

P.s there are also properties on the land generating some rental income. This should help offset some of the interest costs but want to make sure that I will have claim on the rental income. 

Thanks in advance to anyone who responds!