Bitten off more than I can chew ?

[Bravo]

I am 75% of way through building an HPI Cyber 10b.
I didn't know what I was doing and bought a 7.5 turn sensored brushless Team Lossi Xcelorin.
The job lot, including a Acoms 2.4Ghz transmitter thingy and LiPo 5000Mh and clever charger cost £510 !
Will such a motor just strip my gearboxes (4WD) to shreds ?
Will I be able to programme the timing and stuff down and should I be doing this? Just how strong is the drivetrain on a Cyber?
Have I been daft? Have I wasted my money ?
Should I be giving my motor and speed controller to my kids who can make better use of it ?