DinkDonkey30

For reference disconnecting the spark plug wires from the spark plugs will stop the motor from being able to start but does not stop the starter from being able to be engaged. To stop the motor from actually being able to turn over weather it starts or not you have to disable the starter motor circuit. To do that you can disconnect the positive starting motor battery cable, make sure the master shut off if equipped is off,disconnect the power wire at the starter, remove fuses and relays in the starter circuit, and some other more complicated and unnecessary steps. Generally the quickest and easiest is remove the positive battery cable althought any combination of the above will work like redundant saftey steps. I personally don't trust master switches. I've had them fail both open where power couldn't get where it needed to and closed where the switch doesn't shut power off. Disconnecting the postive cable guarantees power isint getting to the motor.If you don't trust that it cut power put the key in the ignition and try to start the motor nothing should happen if power is safely disconnected.As for the prop be aware it can be sharp I wear mechanics gloves when I work on mine but thats more habit than anything I've banged my hands up a lot so I try to wear gloves whenever I can working on stuff. 

I did vinyl repair for a living. You are better off calling a pro if you want it done correctly. The products sold to the general public won’t work reliably on marine grade vinyl. It also requires certain types of products to get the colors to blend and stay in the material. If done incorrectly it can cause irreparable damage. Depending on your area and current damage you are probably looking at a minimum of 75 bucks to repair it.  Most vinyl repair companies will come to you and do the repair on site. Stay away from Creative Colors Inc (cci) they are over priced and generally do poor work. If you have a Quality Repair Service (QRS) franchise in your area I would recommend them. They were both competitors when I was in that industry.