I also appreciate the tips about payment methods and such - I will definitely be taking this approach.

There's an RE Investor/Short-Term Rental Operator that approached me for a long term Lease 2-3yrs initially or 5-6 yrs later on if it works out but he would then rent it out for short-term 5-6 days as corporate rentals. 

The cost to rebuild the propertyThese factors all tie into the appraisal, but overall if it's a single family your best bet will be the comps approach, so just make sure your kitchen and bath is very nice :)

Owner occupancy requirements for this loan is (Typically) 12 months, which I am fast approaching.

They do not understand guidelines whatsoever and are simply paid to take your order for what you want and spit out a rate quote.I like your approach with wanting to put 3.5% down on an FHA loan and house hack to start your investing career.

How do I know how to approach an investor?

I am approaching 30 and have 2 small children, a 2 year old and a 2 month old.

That's a standard approach for many county roads, and is well-known for lower cost and durability.As long as you are trying to improve the roads, don't forget to install paved "parking pads" -- typically 20' x 20' squares to park two cars on each lot.

I would like some typical or atypical approaches that you've used for a guide.

How would I approach the seller into me co-hosting his property for 6 months instead of selling it and what would be a fair plan to make it worth it for both us.