.- you can use any part of the HELOC  you want to ...make sure the lender you are  using for the new loan will be able to  qualify you with the  HELOC  funds  being used  (  some  lenders will  use the  actual payment on the  outstanding  balance and  other lenders  might use a percentage off the entire HELOC max limit )

I like paying my own TI as I know it is paid on time and I can collect interest on the escrow balance until it is paid out.

It's a balance. 

@Silvia BaierYou need find potential partners or investors if you can not fund the down payment, or if your balance sheet is not strong enough.Living in the property would be huge!

Most small balance multi family complexes will not yield a 8%+ CAP in today's rate environment..unless they will consider seller financing..with 30% down there should be some options for creative finance solution.

Your decision should balance financial prudence with your long-term goals.

We seem to have found a happy balance.

As an investor, I've been looking for that area on the North Coast and in conclusion needs more time to be developed ( so there is no guarantee you will have a good ROI due the location )You don't have the same appreciation to get equity and the ROI is not the same there is a reason why is cheaper than other areas. also, the cheapest areas are not the best for us as investors I am not saying that has to be expensive but has to be in balance do you have diligence in analyzing some deals I recommend Santos Domingo for short/long term rentals Punta Cana and Bayahibe too for now 

What is the loan to value (LTV) or mortgage balance compared to the assumed value? 

Your value is 395k and your loan at 90% to that value is $355,500 - what your current balance remaining is of 325k = $30,500 that is how much your line of equity might be minus closing cost. let me know if you still have questions.