The other option is to reduce the projected repair cost as much as possible, and focus on increasing the ARV as much as possible.

Reducing at least one per year and buying if it makes sense without too much effort.  

I wanted to explore modular or pre manufactured to reduce the cost.

If you know what strategy you are going for you reduce a lot of the thoughts you had about switching between fixing and flipping vs buy and hold.

When all of things are newer and you manage the guests well, the actual maintenance costs for a STR tend to be about the same, if not a tad lower, than long term (NOT including the ongoing cleaning costs . . . which again helps reduce the unplanned maintenance and repair costs of the STR).However, in another way you're likely to have MORE maintenance and repair in STRs because essentially you have all the volatility as a normal house, plus furniture and decor, plus a revolving door of guests. 

After talking to my POC today, she reminded me that the conventional mortgage going in my name will greatly reduce the amount that they will lend me and my plan will most likely not work as I thought.

The property is in need of some repair work, which totals an agreed price of $19,000.The purchase price of the property is currently 235k and is a 4 unit multi fam.The seller agrees to reduce the price of the property by the desired 19k amount to $221,000.The problem we now have is we will not have any cash at closing to perform the repairs as we would have if issued a credit.

I am on a search to find an individual to shadow to get some on the job experience.  

It paid dividends for me on one of my buy and hold properties, as I reduced the purchase price $5k, had them pay all closing costs, waited 3 months for them to certifiably mitigate the unit and pay for all carpet replacement.  

The rest of the rehab and estimates look to be on track since we reduced costs by acquiring and pricing out all of the interior materials ourselves (e.g. granite countertop w/ undermount sink, vanity, cabinets, fixtures, etc.) so all we are really concerned about is labor and we have some wiggle room with that.$28K is all Exterior (Siding, Roof, Light Landscaping) and Interior (Kitchen, Bath, Light Drywall, Minor Plumbing Repairs, Paint, Trim) but this number is bumped up a few K like I mentioned earlier.Right now this is part-time but we are working to make this a full-time endeavor and should do so within a year assuming the market doesn't nose dive like it did in 2007/2008.