Nationwide housing bubbles and crashes are extremely rare so why are many people predicting one as if they come around every X number of years or so? 

Unfortunately, many owners seem to ignore these email alerts, and rarely log into their portal to monitor our messages about what is going on with their properties.

Should I combine it with the other four and have one mortgage or should i keep them separate?

If you think load bearing (these are usually exterior walls) were modified that's a little more rare, you might need an engineer. 

I will be using an FHA loan combined with South Dakota Housing which will cover my down payment and I will have to repay my down payment if I refinance or sell the property.

Update, In texas you can not exclude your spouses debts. you can only keep the spouse off the loan if your income alone can support the combined debts plus the new loan.

Would love to combine forces and get a deal done.One piece of advice: rather than starting with a laundry list of specific criteria, you may have more luck starting out with 3-4 criteria and then looking for all deals that meet those criteria.

I saw a combination of “turnkey” and gut renovation properties owned by the city.

If you are going to stay local a combination of local and online networking. 

Most of the deals I have looked at fall apart due to lack of deferred maintenance, tax liens, full market expectations, or some combination of all of the above.