Your orchid should only be watered when the growing medium is dry. Make sure to allow that water to soak the medium but drain any excess water from the plant so that you do not get root rot. It is normal to get roots over the pot. These are called arial roots, In nature. The roots should be a white color. One sign of over watering is when the root stays deep green. If you see more than two of these roots coming out of your container, it is time to go to the next sized container. Make sure when you repot the plant that you clean off all the growing medium off the roots. Make sure to clip off any damaged or dead roots with the scissor that you have wiped with alcohol. Sounds like your plant is doing nicely.