1. A friends plugin is great for large networks so there is less "you hacker i hate youuuuu" from squeakers, but I think staff should be able to speak with players, even if not friended. I think a good solution would be a /report or /helpmestaff command which would connect you to an available staff member, for help.
2. like dailytuber said, we like it to be kept to have a "medieval" feel. There are many mods and plugins out there to create your own gun warfare, and I am sure its possible through command blocks too! ^-^
3. That can get a little complicated. Some people like to have different minigames, like survival games, or paintball. We can agree, they are pretty fun. But if there were no rules other than "No griefing, no swearing and no hacking.", I'm sure people will find ways to exploit those rules. Going way to specific will ruin it, but something less general would help out sophisticated players. Keeping some general restrictions can keep the server fun in many ways. Such as survival. Would it be fun when you have bedrock bunkers with stacks on stacks of diamonds? no! There should be a limit, but a nice owner that is willing to give you some iron to start off would be okay.
4. That is optional. There are many other options than, killing a dragon. You don't have to technically kill endy to win the game! Just build a massive city or play on a short minigames server! You could also use some fancy mods/plugins, or like i said earlier, use some massive commandblock mechanism to have a pet dragon!
5. Again, like dailytuber said, google is always there for you, unless you have no internet connection
Good day/night!