I notice the older guys and hvac business owners feel threatened by diyers, their workers on the other hand, seem tickled that you are taking an interest in learning what they are doing, and have no problem sharing their knowledge.
For me, I found a guy that has no problem checking and starting up a system. I may still hire someone to mount the inside unit though, it's either that or build a jig to hold it in place while I make tubing connections. They sell a pretty nifty one for less than $100, and the design (plastic) is something I could easily turn out in wood.