I'm having similar problems.

1) My fuel cutoff switches work, but I have trouble restarting. After pushing CTRL+E it took several automatic tries before the engine started. Not sure if this had something to do with bleed valves or incorrect settings in the overhead panel, or if it was just a bug. The effect was that I heard the engine startup sound - then it would abruptly shut off. Then again - and it would shut off. It did this about 5 times, then Engine 1 started. It took even longer for Engine 2.  This was with the stock CS 757 v2.2 sounds.

2) I clicked the Fire Shutoff switch, but then there's no way to turn it back! Left or Right clicking has no effect.

Can't tell if these are bugs or if I'm doing something wrong.