No worries, we all start somewhere!
Not an individual macro, no. You can select Stop Editing Macros from the View menu but that applies to all macros. What I do when I don't want to inadvertently mess up a macro is collapse all of it's actions, and then group them all together and collapse that group, giving it a custom title like "don't screw around with this because it already works great and if you change something you're just going to break it and then you'll be kicking yourself the rest of the day" 
Not that I'm aware of (although some hidden preferences can be adjusted via Terminal, I'm just not sure if this is one of them). But you can adjust the timeout on an action, and then add it to your favorites via the native favorites feature of KM10 or via @DanThomas KMFAM Favorites macro.