Rental properties come in several flavors... short term, long term, etc.  

Will you use the HELOC as a short-term bridge, or plan to hold it longer?

Credit pulls for the same type of loan within a short window (usually 14-45 days) are treated as one inquiry, so your score should be fine.

The short answer to you question is yes. 

Short-term rentals of non-owner-occupied properties will also require a special use variance which is obtainable by starting with the completion of an application in the Zoning Department."

Short term my credit score did take a hit, but once the promotional transfers were paid off, my score jumped higher than it was before.These days, the "pure" zero percent transfers don't seem to be around anymore as they typically charge a 3-5% balance transfer fee as part of the promotion, but this is still better than current HELOC rates.

Underestimate the costs and come up short needing the funds?

Quote from @Anil Shah:  Short answer - if they originate a loan that they want to sell to Fannie Mae and Freddie Mac, they need to follow their guidelines.

Your interest rate, on a fixed rate loan, should remain unchanged and your mortgage should not be called due.However you should still confirm that this is the case with your lender (and read your mortgage commitment) out of an abundance of caution and because some loans and programs do require a longer seasoning period.

Many times, when i replace a water heater and take a look into some of the short pipes that connect, they are approx 80 percent closed.