It's now "Somewhat" working. Following MCWopper's comment about 2 monitors, I disabled my second monitor in the Nvidia Control Panel and was able to get past the GDICaptureSource error. I was able to get 2 of the FSX Missions to work, but for some reason, on Free Flight and some of the other missions I tried, after everything loads and the window on the monitor changes to the 3D view, FSX crashes. There is no crash log created, but the event viewer has this entry:
Faulting application name: fsx.exe, version: 10.0.62615.0, time stamp: 0x559f9a9a
Faulting module name: d3d9.dll, version: 0.0.0.0, time stamp: 0x5748353e
Exception code: 0xc0000005
Fault offset: 0x000be046
Faulting process id: 0x18b8
Faulting application start time: 0x01d1c1319d3389d7
Faulting application path: D:\Steam\steamapps\common\FSX\fsx.exe
Faulting module path: D:\Steam\steamapps\common\FSX\d3d9.dll
Report Id: df58019f-2d24-11e6-b242-010101010000
OR this entry:
Faulting application name: fsx.exe, version: 10.0.62615.0, time stamp: 0x559f9a9a
Faulting module name: d3d9.dll, version: 0.0.0.0, time stamp: 0x5748353e
Exception code: 0xc000001d
Fault offset: 0x0004a069
Faulting process id: 0x16e0
Faulting application start time: 0x01d1c1317196806b
Faulting application path: D:\Steam\steamapps\common\FSX\fsx.exe
Faulting module path: D:\Steam\steamapps\common\FSX\d3d9.dll
Report Id: d4a24d8a-2d24-11e6-b242-010101010000
I did go ahead and purchase the FSX version though as I'm sure these other issues will get worked out.