How many discs and how long it takes to install depends on how much scenery you tried to install. We recommend not starting with the entire world as it can take a long time to complete the install, so if you picked less than the full world it might just be due to that.
Did you happen to try the demo before purchasing the DVDs? Looking at your log, it appears that your computer may only barely meet the recommended hardware specifications. For example, the GPU listed is Intel(R) HD Graphics 2500 which was released in 2012.
I would recommend going to the main X-Plane folder, then to the Output folder, and moving or deleting the entire preferences folder. That will put you back to all defaults. If that allows you to get the sim started, please try to skip the opening tutorial sequence and go straight to the main menu to access the settings. Try setting all the graphics options to their minimums.
Otherwise, if your computer doesn't meet the system requirements, please contact customer support at [email protected] about a return or exchange.