also wondering if you are pleased with your Return Percentage when not including the Principal Pay-down on your mortgage and the estimated Tax Benefits  - Thank you!

Regarding, the Partnership, do you have a percentage in mind based on the variables mentioned?

If so, what percentage or amount is typically required?

Percentages vary depending on your strategy but here is generally how I use my excess cash from this portfolio: Say you have extra 1,000 bucks after paying your monthly expenses and putting aside money for reserves: I split it out in the following manner. 1) Additional rainy day fund for CAPEX and repairs. 10% 2) Additional Acquisitions budget 50% 3) Additional Debt paydown 25% 4) Stocks / Bonds/ Pay myself. 15% I definitely prescribe to the pay myself first , and have a more conservative approach when dealing with debt .

The amount may change, Zillow is often within a considerable level of error  The bank is going to loan you a percentage of that value. 

It is the most crude screening tool and the actual percentage will vary by area and your goals. 

One idea I've come up with is offering the seller a small percentage of the profits after the house is sold.

There are quite a bit of 3rd party sites and agencies that will list your property for short term for a percentage/referral fee which will be helpful as you get started. 

I would rather keep my cash any day than put it to work on a mediocre property and area and hope for the best strategy.If you are worth millions and want to take  a small percentage of your money and take a roll of the dice on something that is different than saving up a long time to get started and buy a mediocre property and it becomes nothing but headaches and saddles an investor with bad debt so when a good deal actually comes along they are stuck.

I know there is always the possibility of having to pull that out earlier if something happens with the unit or the lease agreement, and with that would come penalties in the CD route, but the possibility of penalties vs the potential gains may outweigh the risk, especially if you keep a certain percentage as a back up and not place all security deposits into a CD account.