Brian:
you have a challenging position that puts you in the view of owner,AHJ,your employer, and the hands who use the tools. Three points I'd make:
1)don't procrastinate- keep your records up, and stay ahead of the project.The PM is expected to give instant answers to status questions. Document slowdowns,extra degrees of difficulty, existing problems in remodels, and a whole lot more.
2)keep everyone who should be in the loop informed.This is lot of legwork,emails,and just plain personal contact. You'll get results if people know you are up to date and keeping an eye on things.
3)assume nothing, check it out. I was PM on a conversion of a big FA system for a performing arts center. The system had been in ten years,and was failing. My assumption that it had been wired correctly was wrong. No fault of the original electricians, the FA salesman left them to fend for themselves, and a lot of mistakes were made, that never shopwed up. For instance, the concealed backbox for the speaker strobe,had an extension box in front, to add more space, but someone decided to pigtail the strobe circuits instead of looping them,to save space. This T-tapped the strobes, and there was no supervision. we had to go through about 140 boxes, and change the wiring just to bring it to compliance. This was a state job, no inpectors who understood FA systems, and a rush to get a very visible building up for a grand opening. Know what you are getiing in to,and good luck.