enough room for an angle grinder to cut off the bolt? or maybe an oscillating tool or reciprocating saw? but if you cut the bolt how would you get the bolt out or maybe i'm missing something...
It just needs to be reset, look in your owner's manual for the procedure or try this:
Switch the ignition ON. Make sure that the power window lock switch located on the driver's door is not depressed. Press the switch and fully open the window. Pull up the switch to fully close the window and...
I suggest painting the entire calipers gloss black, I have used Rustoleum Engine Enamel spray paint on calipers and it works just as good as the much more expensive "caliper paint".
You really shouldn't drive the vehicle with a misfire as it can ruin your catalytic converter and they are costly to replace.
Is the metal sound you are hearing like a rattling sound? if so it could just be a loose heat shield on the catalytic converter, most people just remove the heat shield...