The most useful thing you can glean from a credit report is their debt income ratio because you would want to know if a persons income is over committed, but a credit scoring is useless in that context because it rewards people that maintain repayments on what might be unaffordable levels of debt.

I'll personally take 5% of 100k cash invested ($5k) on a non/lightly-leveraged property all day before 10% of 100k cash highly leveraged into 20 properties making 500 bucks a year each just based on a risk/reward tolerance. 

Of course now a days many say a home is a liability but depends on where you live I happened to buy mine in Silicon Valley and that one move was very timely and turned out to be financially rewarding. 

I also found this article to be helpful:  https://www.biggerpockets.com/renewsblog/risks-rewards-renting-illegal-immigrants/

It can be such a rewarding thing to do, and even though I have almost given up hope at time, as all my funds were lost after waiting almost 1 1/2 years for the cases to be settled.

Need to weigh risk vs reward.

I have the cash to use but would prefer to keep it in pocket and utilize a zero interest period and cash back/rewards since ill be spending $40-50K. 

Any debt increases risk, and therefor increases the reward as well.Knowing you are in CA, I would still start with the cheapest house you can find, but also one with as close to only cosmetic upgrades possible (read: as little work).  

As long as you know and consider the risk versus the reward and if it is something within your strategy its good. 

Verifying rental history can be particularly crucial in assessing the reliability of tenants in Class C and D properties.In the end, aligning your investment strategy with the right property class and being aware of the associated risks and rewards is key to building a successful real estate portfolio.