Welcome to the Forums and congrats to your new laptop!..
(Just curious, what made you choose the G74 over the newer G75?)I would be doing these things, if I were you:
-Do a "physical check-up" of the unit for scratches, cracks, etc.
-Power on the unit (with the battery and AC) and check if Windows, Drivers,
and applications work consistently. It's worthwhile to use DPC Latency Checker in here.
-Power on with battery only. Drain and recharge it by using the Windows' Power Options > Calibrator.
-Install some stress-testing programs (Furmark, any power-hungry games, etc.)
-Update Windows,
manually update drivers (uninstall ASUS Live Update).
-Fiddle, fiddle, and do more fiddling on the unit for some time.
Since you'll be having an SSD soon, I strongly suggest you do an OS clean install.
Many of us here are satisfied users with the OS clean installation.
ADDENDUM: Many of the bloatwares are unnecessary. But a few of them may be
useful to a particular user. The bloatwares I have are:
-AI USB Charger (to recharge my phone via the G74)
-Power4Gear Hybrid (for the ROG button to function as 2D/3D toggle)
ASUS G74SX-3DE