Are the LED flashlights waterproof?

yes, they are waterproof. pls dont worry .

Is the amber white alternating?

Hello, if you mean alternating amber white color, you could note your needs when you place an order. If you mean alternating amber white pattern, you could choose "WHITE AMBER" at color option. Here is a video showing the patterns: https://youtu.be/sdGBZUebooQ

Does this have a magnet mount ?

Hello, sorry for your inconvenience, this doesn't have a magnet mount for now.

Is there wire extensions available?

Hello, you can note the length of the wire harness you need when you place an order.