Welcome to S2 Fir3Spell
Anyway, I have throttle cut on upshift off, but I have throttle cut on downshift on. With it off with upshift, it doesn't make that much of a difference, because all the cars usually shift fast enough to avoid engine damage at high RPM's, but I have it on for downshifts simply because I like to drift sometimes, and this prevents me from hitting the danger zone on downshifts mid-turn.
Some more advice: Use the shifters on the wheel and manual transmission. Turn off the shift light, and learn when to shift just by listening to the engine. This way, when braking for corners, you will know when to downshift with each car, in the process using the transmission as a brake, and not hurting the engine.
Hope this helps, and can't wait to race you!