My question is, what is the proper approach/verbiage so to find out how much available capital they're willing to lend so that I can figure out how to properly use their funds i.e. for help with a down payment, a rehab loan, closing costs or a partnership?

I am hoping that agents will recognize the potential for partnerships on future investment purchases even if one doesn't exist right away. 

Hi!  I’m a new investor having less than 5 properties, do not have a w-2 job, excellent credit.  I want to build more capital and expand my portfolio, but afraid I may be running out of finance options.  
I have some...

However, I don't have the capital yet for a down payment and such so I've been looking into partnership opportunities where someone will front the cash for down payment and renovation and I handle the rest.

First advice before you do anything else, consult an Attorney and get a solid partnership agreement in place.

3) Partnership: If I can find a partner but also make sure it's a good deal for myself.

I would like to hear about your “Factors to Success” what are some of the key actions, habits, partnerships or other things that have helped you with real estate investing.

How difficult will it be to find investors willing to put up 80k for 50/50 partnership in new built duplex that only cash flows $250 per mo.

Most people also have 1 or more partners that come in to the deal on the general partnership side. 2.

There are certain back-up strategies that you can look at such as: Net Lease Properties (Triple Net Lease) Delaware Statutory Trusts (DSTs) upREITs (1031/721 Exchanges) or, if your exchange fails, a Qualified Opportunity Zone (QOZ) The Qualified Opportunity Zone is not an option for your 1031 Exchange because they are structured as "funds" generally in the form of a multiple member LLC, which would be treated as a partnership for tax purposes.