Why are you using rules of thumb and not using the results of the thorough inspection by a great inspector that you are surely using and would be an idiot not to base your numbers on? 

You will want to get a professional inspector and contractor that you trust to walk the property on the outside if you can't get in. 

NSPIRE will be used for all HUD funded housing programs.With NSPIRE, inspectors for HUD-assisted and HUD-insured housing will be able to conduct objective, defensible, and consistent assessments to evaluate housing conditions.

Particularly when you are the new owner and not the one who actually did the unpermited work.However, they will not give you a pass....you will have to prove to the Inspector that the work was done 'up-to-code', and if it is not, you must bring it into compliance.

If accepted, I have my inspector inspect the property and provide me a report on the state of all systems and structural. then I use this report to build my scope of work and know what repairs need to be made. then I type out this list and solicit bids from 2-3 contractors/GCs/ handymen depending on the nature of the rehab.

Networking with other investors at local REIA is a great way to do that and also a great way to meet realtors, wholesalers, contractors, inspectors, property management companies and anything in between. 

If you aren't sure who to choose from, ask each of them for a meeting/consultation to break down your goals, the market, and the acquisition process.Once you've selected one, have them draft the offer for you and take it from there.The best agents are responsive, knowledgeable on the local market, have a strong supporting team (i.e. lenders, title, inspectors, title, etc.), and know how to put together a deal.As @Michael K Gallagher mentioned, you'd want to clarify whether or not your agent is also representing the seller.

Being out of state, you will want an agent who has good relationships with reliable inspectors, title companies, contractors, property managers, lenders, wholesalers, insurance agents, other RE agents, etc.

A reputable home inspector would be able to point you in the right direction. 

It doesn't matter, just choose one and use it.3) This is just about finding a good local real estate photographer and inspector.