Update:
Yesterday swathdiver (James) was nice enough to come over with the Tech 2 to see if we could figure out the P0442 and check fuel pressure to diagnose the starting issue. Unfortunately the fuel system monitoring was not an option listed for my particular vehicle. Not sure if the 2007s support this or not..
On a better note we did some experimenting with the EVAP purge valve. With the engine running, the vent valve closed and the purge valve commanded open (even to 100%) there was never a negative pressure generated in the fuel tank according to the fuel tank pressure sensor. In other words the new purge valve I purchased and installed a while back had to be defective.
The purge valve is a Duralast lifetime part from AutoZone. This was against my better judgement as I usually only purchase OEM replacement parts. This is exactly why.
After James left yesterday afternoon I hopped on Amazon and ordered a Genuine GM EVAP purge valve.
This afternoon the new part arrived and I installed it. The Duralast part was definitely defective because I am able to suck through it with ease. No resistance at all.
Now we wait and see if the code comes back and/or the starting issue persists.
Thanks to all who have been helping me with this