If I could find an investor with enough cash to fund the whole thing it would make it way more beneficial for the both of us being able to cut out the bank.

I also have a lot invested in Mutual Funds...and I run into the dilemma...hmmm should I put an extra 10K down on this house or would I do better putting 10K in the market and making ~7% each year.

@Clayton SmithCost Segregation would be very beneficial as you would be able to accelerate depreciation.

Is it beneficial to refinance into a rate and term now or better to wait to do a possible cash out refinance relatively soon?

As far as far as showing we have 3 months reserves on our then 3 properties, we don’t have that in Cash, but absolutely do in investments (stocks, mutual funds, ETFs, etc).Good to think of it in this way though.

If at least 10 years, it will almost for sure be beneficial.  

If it was me I'd invest 50% in apartments, 10% in a long term/tax deferred account for later in life, 20% in stocks/mutual funds, 10% in liquid cash, 10% for a risky investment or something you've always wanted to try and 10% for fun, toys, vacation, etc.

I figure I may get some returns in s mutual funds or something on the cash.

I want to get started with rental property investing, and without waiting 2-3 years to save up 20% for my first rental property, would it be beneficial to use equity in my personal house with a home equity loan, to get started?

If you form an LLC and go for a loan, first off, the LLC has not income or assets so will have trouble qualifying, second, you will be in a commercial loan which will raise the rate a point or two and have a shorter amortization and probably a balloon payment.This may be a little over complicated, but if it were me, I'd do the loan in your name, put the house in a trust right after you close and make an LLC the beneficial interest of the trust (basically just run all the expenses and income out of the LLC because a piece of paper in your filing cabinet says you can).