I thought at this point in time it might make more sense to start investing in RE projects that can offer above average returns ( 10+% p.a.) with relatively low LTV's and first lien positions. 

Primary much easier offers a higher LTV/CLTV on renovation or 203K.Investment - those can be tough but easier to do the renovation after you own it and either have equity to pull out to renovate or use equity from another home through a cash out refinance.If the renovation costs will be $50K or under you can take out a personal loan after you buy the home and do it yourself.

Leveraging current equity by refinancing the property and taking out a portion of it through a cash-out refinance is one such tactic.

I'm also getting the financials straightened out with a CPA firm who specializes in this, so there's no cash for investing yet, but there is 100% equity.

If HELOC on an investment property is not an option, is there another way to pull the equity for that property to buy another investment property? 

When we got the trustee sale guarantee back from the foreclosure trustee, it showed the HELOC in first lien position because of the page number and recording time. 

If my short term rental is not a positive cash-flow could it still be a good investment given the tax advantages?  

There are a lot of wholesalers who are buying lists of properties in foreclosure / default and do not realize this in many states is considered predatory.As taxes and insurance increase along with homeowners having equity, states will start to catch on to this and my guess is start going after more of these wholesalers.It will be an easy win for them as most wholesalers act as brokers illegally (do not do double close) and do not let the homeowner know all the options available to them (modifications/ bankruptcy), they are out to solely benefit in their behalf which in itself is predatory

Unfortunately I think my family position has us past the ability of house hacking.

Any market that you find a property that has positive cash flow or you can flip or do a BRRR is good.