This is just my experience with HELOCs, I’m not licensed to give any kind of financial advice, check with your accountant or financial advisor to ensure you are utilizing the correct financial products to reach your goals.

And I'm here to be financially free.

So well that I am looking for financial partners/investors to keep expanding.

Keep in mind the financial resources do not have to be yours, they just have to be money you have access to; not just banks but also friends family, hard money lenders etc. 

Some places are sensitive to fluctuations due to local circumstances. 

Would you suggest I try to qualify for financing while still married, (obviously I would agree and sign whatever that husband would not be responsible), or do you suggest that I wait until afterwards to avoid any legal/financial complications or wait and find a way to use OPM?

A new LLC has no financial history, and so won't qualify for a loan on its own.It is possible to get a true non-recourse business loan.  

Your best option would be to find a place for her to rent that she can afford with out needing your financial assistance , one you do not own, and rent your own place to a tenant.

Now whether you should do so depends on the circumstances.

Don’t ever let any financial professional tell you that “you don’t have a choice.”