I want the passive income of rental properties, and I love the idea of multi-family units.

Can one contribute 100% of their earned income up to the 55k limit? 

Then, in 2015 I decided to look into truck driving school and realized I could make a descent income with a lot less work and go to school basically for free.

How does our shared mortgage effect my individual debt-to-income ratio?

Theres not much you can do without income

It is better to do a deal than skip one just because the dollar amount for financing is high.Good luck in your search and know that if the numbers make sense, you have made the right choice.ya know I would have agreed with this pre 08  but these days most HML want good credit  and proof of cash reserves and cash down.. for inexperienced first time type buyers they may not even do one.. unless you have massive down and cash backing you up.. it gets very easy when your have a nice track record.. but most HML are not little down crappy credit no provable income.  

So essentially, I would be paying 300 in utilities plus 75 (difference between the 900 rent and 825 income from upper unit) for a total of 375/month.I own and manage several SFR's and multi-family properties, but have never gotten involved in a lease option.

He wants in on any deal as to expand his income streams.I have decent credit(655), and have 6 years in my career industry.

If you are leveraging the property, and the cash "in" is the DP (20%), then a property with only a 10% CoCR is a terrible deal.Since the CoCR is based on CASH, and most likely the income side is the cash flow, that cash flow should be the same for the next few years. 

This way you have a corporate shield between you and a tenant.