What would be the repercussions of not being able to occupy the house with an FHA loan?

@Paul Charles Bayliss since you live in Texas I am assuming you will not be occupying the triplex, but wanted to confirm. 

I've found a property for sale for $49,000 with 4 mobile homes on it,  all currently occupied.  2 tenants pay $475 a month,  $350 from one and the other owns the home but rents the land for $200.

Rehab costs are rolled into my loan (don’t need to seek financing elsewhere)Holding costs are decreased as its interest only during the rehabOnce the rehab is completed, instead of staying with the commercial loan, I refinance the rehabbed property with the conventional loan (as I still owner-occupy) which will Lock me into a lower -fixed interest rateAmortize the loan over 30 yearsCash flow…BOOM!!

Dont try to force yourself into that little space that some or most people occupy. 

I have a listing in a less desirable area at$108k here in Tulsa. 2/1/1 plus apartment 1/1 both are occupied apartment is 650/month and house is 800/month.

I would recommend finding a broker that specializes in this type of financing.The perks with FHA financing include - the option to put down only 3.5%, - it's available for 2-4 unit properties, - and the underwriter can use 70% of the rental income from the occupied units towards your ability to repay the mortgage. 

There is a big difference between an occupied building and vacant.  

The reason I have chosen to start with 2-4 units is because they qualify for FHA loans and I do want to house hack through this process as well so I would be living in a unit for at least a year (meeting the limitations of the fha loan), getting to know the tenants coming in to occupy other units and understanding exactly how it is to live in the property to be able to provide the best quality of life for the tenants.

Non owner occupied conventional mortgage if you buy a rental 1st.3.