1. Why is it hard to post "IN" on a game thread? It takes all of five seconds. Just register, get AV'd, post "in" on whichever game you want to attend. Show up. Most fields would prefer you sign up so they know who and how many players to expect.
2. No you don't need the orange tip that is a US law
3. Paintball goggles are usually masks like Dye/JT's since certain fields insurance policies don't cover ballistic goggles only. Some fields are ok with ballistic z87.1+ rated goggles and a lower mesh mask to protect your teeth depends on the venue.
4. So you don't lose your teeth and end up with a huge dental bill. Usually its highly recommended but player optional unless a field requires full face protection.
Hope that helps.