What will it cost to get the mold remediated and what it the rest of the repair cost. 

I would be very surprised if you have any remedy here other than repairing the defects yourself. 

My insurance covered a bioclean company to come and remediate the damage: That cleaning included deoderizing, removing affected flooring and removing and disposing a mattress.

They have provided the termite report, and shared what the suggested remediation is (but even that report admits that they cannot see all damage until siding is removed). 

Unless your willing to go to the mat and sue on the note to get a judgement ( assuming its legal to do so in your state).your out the money.. and the property has to be your remedy.. in all the years I have been doing this its EXCEEDINGLY rare that you will collect a deficiency from someone you owner financed the reason they owner financed in the first place is probably credit and other nik's in their credit or borrower profile.

I guess it's fortunate you are able to least keep visibility on this particular one and remedy the situation quickly! 

OR can I go to the City of Phoenix and get this remedied on the grounds that it was the responsibility of the (RTO/Owner Financed) resident?

At times, the odor was so strong you can smell it walking in the main entrance into the lobby.There's been some discussions here on remediating it with chemicals.

Would you pass or perhaps negotiate the price to have someone actually remediate this? 

And if they do they will probably give you the opportunity to remedy it (transfer it back into your name).