I'll give this a try...
1)The red wire off the regulator/rectifier is what charges the battery. If you are using an ammeter this wire needs to go to it so it reads correctly.
2) The kill switch would need to connect the small stud on the front (when installed in a max) of the engine near the rectifier to ground to shut the motor off.
3)I think this refers to the fuel solenoid on the carburator. Not all briggs engine use these. It has a red wire and needs to have power to it when the key is on.
4)Turning the switch to stop kills the engine by grounding the spark, and by shutting off power to the fuel solenoid.
Recreatives has a wiring harness available for a Briggs Max II, but you would probably have to replace the key switch to use it. A wiring diagram is also available from R.I.
"How deep of water does it float in?"