I am looking to find a credible contractor that could do a walk through to see how much work this place would really need.

I have 22 STRs that I rent out to contractors. 

The only issue I see is if a contractor gave you a lump-sum price and you are trying to allocate the cost.2) Yes, I am on the opinion that a house is considered placed in service on the day it is listed for rent as long as it is being legitimately put up as available to be rented. 

He told me to obtain a mechanical permit and building safety inspection for the heater and have a licensed contractor conduct the work per California state law.

Current price is $113k , she was saying it should only need about $7k-$8k in rehab and she should be able to sell it for 150k, which is on pa for comps in the area.However, my contractor (who's a close friend but is a legit contractor) went to take a look at it with me & believes the rehab is gonna be closer to $12k-15k and doesn't believe the realtor can sell it for what she's saying she can.

For the most part a team is just an agent and a property manager if you buy turn key, maybe throw in a contractor if you are doing rehabs, but in general yes you should know who all these people are before you sign on the dotted line if you need them.

One is 9 years experience in the construction industry working with highly sophisticated owners, end users, and contractors. 

I had my contractor fix the leak, pull out the wet and moldy drywall and clean the effected area with moldicide.  2 sqft of moldy area was found and maybe 10 sqft of drywall was removed from each garages in this duplex. 

We have a contractor but will consider other options as well.

Go to REIA or other real estate meetups, speak to experienced realtors that are long-term investors themselves, try and find a police officer and or fire fighter that invests--they know the deal, speak to licensed contractors in the area you are interested in and find out how they feel about working there.Hope this helps.