I've had my current job for 2 1/2 yrs making 75K per year and have a clean background but before I had my current job I was unemployed for a while and ended up filing for bankruptcy causing my credit to take a huge nose dive (sub 500 range). my Question is: to avoid the credit requirement (I wouldn't be able to find a co-signer) would I be able to put an entire lease down as a security deposit and pay my rent as usual so long as my income qualified?

It was pushed back because the buyer needed a co-signer.

I would love to put together a co-living house project and I have been doing a little bit of due diligence.

We again bought another house in 2017 as a co-borrower.

My situation is I have a decent down payment of 15,000 and a great credit score but can't get a loan without a co-signer since I don't have sufficient income.

They will not issue a CO if the unit will be over-occupied, and if the occupant count goes up subsequent to the issuance of the CO, the owner would probably be fined (they fine us for everything else when we run afoul of their statutes, so I'm assuming this would be no different). 

Thank you for your response.I started in 2015 renting a house to a co-worker of mine and it went horribly as you might imagine.

remember the property has to be able to maintain a CO and be livable (broad brush concepts) otherwise why should the lender underwrite the loan?

Also are there ways to invest without credit score such as getting a co-signer to sign the loan?

A lot of towns in NJ will issue something like a CO waiver (or at least they did when I was there several years ago).