[wizard67]

1. Assuming the bottom end is tight and well built it should take a 100 shot no problem. And those Afr's should definately help it on and off the bottle.
2. The 93 octane shouldn't be a problem just make sure you take out about 2-3 degrees of timing for the 100 shot. If you are really worried about it, you can go to a step colder spark plugs too.
3. You should be just fine with your mechanical pump, if you step up the shot to a 125-150 you might should consider an electric pump with a regulator.
4. Although I don't own a manual tranny, I built and tuned a manual tranny drag truck for a friend with nitrous. We never ran any type of interrupter switch on his nitrous set-up. As long as you let go of the button before it revs to the moon you'll be ok. But if you have a slow reaction, or miss shifts often you might ought to get a switch for it.

Just to make you feel a little more comfortable, I ran a 150 shot at least twice a month to a cast crank, stock rod, and CAST piston motor on 91 octane for more than a year with absolutly no problems.
Just pay attention to your motor, and don't neglect the nitrous system.