This is a very common situation and I am surprised that seems to be some much confusionBuying a house as is simply means the seller is not making any repairs but And I repeat but your did not waive any or your contingencies unless expressed in the contract1- Right to due diligence  as per California law2- Right of inspection3-Appraisal and financing contingencies, title issue  etc etcYour agent should have sent out an addendum cancelling escrow if seller does not respond to your requests for repairs or whatever you wanted before your due diligence period expires  The emd is yours to keep if your sent out the proper notices during the time periods  allowed  The agent should know this it is Read your contract to confirm 

If I had 300K I would either spread it out as the downpayment between 2-3 houses and have a reserve for emergency repairs. 

I was surprised when they told me that they have never done credit checks.

To my surprise the house was on his list of homes.  

A couple of caveats; 1) As this is an older property, it would not surprise me if the expense ratio was higher 2) Carrying cost are not included 3) Unless you have done this a few times before, renovation costs tend to inflate 4) Your time / effort is also not included.

Before I buy an investment property I'll have my 6 month emergency fund and add to that as I grow my investments accordingly.

My credit score is 815 and I have six figures in emergency savings.

If it's as good of a deal as your numbers suggest, I would be very surprised if it sits for long. 

It seems like you offering 150k but also telling them that you would be willing to go to 180k would just mean that, surprise, we got an offer for 178k. 

New and broader range of risks will emerge in future.