Please do a very good connection, high waterproof level, and weather resistance, which can keep it for a long life. To avoid voltage drop, normally leave more than 20% voltage to neon light, which is better.
Firstly measure the required length you need, so that you can choose the suitable lengths and avoid waste or insufficiency. You can cut the length but you have to get the connectors, end cap, and glue to make it waterproof IP65 or IP68.
Yes, Neon light is incredibly safe to use, is well looked after it treated with standard. Nowadays Neon light is more and more popular, with businesses all over the world using neon light to make their advertising.