After six months of STR performance, transition to a DSCR loan or portfolio lender refi for better terms.2. 

First, I’m not really seeing enough cushion in certain popular areas for investors to realistically hit a 30% profit margin.

Lower costs mean better profits and fewer financing headaches, plus taxes and expenses are much lower than in places like Florida and NYC.

If your investment is still profitable with the increase, then press ahead.

The price you pay for being part of the Disney World spoon-feed of guests is that the barrier to entry for profitable STRs (ones that leverage close to or max LTV) is very, very high.  

I hold a w-2 job currently and considering transitioning to holding some properties.

Angel investors might be interested, but you'll likely have to give up a portion of the ownership or future profits, and there could be potential complications in managing the investor's expectations and involvement.

I used the 75% rule on the income and added it and my DTI without the rental goes from 24% to 38%.Or does it just allow me to just take the net profit of that rental and add it to my rental? 

Some of these strategies (though not all, and possibly not the most profitable) are the subject of constant discussion on BP. 

@Nate McCarthyProfit Splits and Contributions:Dividing profits proportionally to investment (2:1:1) is common, but you could also account for sweat equity if one party is doing more work.