Dealing with Contractors, inspectors (lender/city/county), material-men, is one of the most difficult aspects of this business. Your personality has A LOT to do w/ how you deal w/ those things.

If you tend to believe the best in people, its going to be rough.

If you tend to not believe people, its going to be rough.

The ONLY way to have success with any of those is to have your facts in a row, and to trust people followed by verifying everything you are told; until you know it 100% w/out verification. 

Finding "Facts" in this business is REALLY difficult however. Not many are actual pro's or experts but instead just want whatever comes with the title. i.e. building inspectors make 35-45k a year. But, if they really knew everything about construction they could get a superintendent gig working for a prop manager or construction company making double that, but they would have to ACTUALLY know what they where doing.

The point is this, you can struggle through and make things happen w/out paying for real professionals. I see it done all the time. But you can also budget into your projects to pay people to take away your headaches, and allow you to just verify facts and cut/collect checks.

There is nothing wrong w/ hiring pro's, not everyone can hire 3 dudes off the corner and flip a half a million dollar home. Its not "ability" its personality. 

I get hired by billion dollar REIT's to evaluate their acquisitions (mostly for rehab / repositioning scope/budget) and to do suggestions for long term maintenance issues. They aren't experts on any of that, and getting a bunch of bids would require 100's of hours of work by people who may not ever find the truth. So it has more value to just pay me. 

However, I also hire pro's when things are out of my ability. i.e. I hire engineers to review my designs/plans to make sure I am not overloading walls or violating some rule I am unaware of or forgot about. I am a "pro", but that means I know my area and don't try to act like a pro where I am not.