He wants to put me on his shares or shall I say stock in the co-op so it would be basically 50/50 in the unit.  my question is just how would this affect me at all because I currently own no real estate but I plan on ...

Ask for a co-signer on the lease with verifiable credit.  

@Tom Parris is right. i just bought my second properties 3 units in NJ as investment home and my credit score is kind of low @716 when i applied for the loan. i went to the mortgage broker and the rate is 5.1% with 25% down payment 30 years fixed. i know that is high and i probably try the local community bank like everyone else advised here Refi cash out for another property. i tried to have my father move to my second property as his primary residence as he is also a co-borrower due to my stupid car payment. it ended up with 25% down payment and my large amount down payment tied up to one property. i can't get another one like everyone advised. i wonder if anyone can advise any ways to get another property without saving another 25% down payment. i see something i like and the numbers make sense but ran out of funds.

She has a pet(dog) who will be with her during the time she visits/stays at the rental property.The GF is not a co-applicant but just visits him and stays a day or two.How do I address this situation since we have a "No Pets" policy in all our rentals.Should I charge a pet fee every month along with a pet deposit or should I say "No Pets."

I likely will not have a co signer and my biggest worry is the lender seeing my 15k income.

Sometimes I don't do a co-signer but that's not the norm.

As long as their credit score comes back clean, and they haven't missed a payment, I don't see any red flags.      1) Increase late fee, or even better--  set up the lease where they get a discount if paid via the first.    2) Require a co-signer3) Up the security deposit

I keep hearing that it may be better to invest in student rentals, as I can require a co-signer; however, I am hesitant as they are usually irresponsible and cause more damage. 

I suggested asking for a co-signer that has verifiable income but the partner believes that would be taken as an insult by this applicant. 

As far as I can tell, my options are some sort of personal or project loan with a co-signer as I do not have an income (I am a student currently) with a refinance at a lower rate later, a personal loan with plans to sell the property ASAP, or sell it without any rehab done for a lower price of course.