Setting up a Roleplay server

Hey guys! I'm about to setup a roleplay server. I've got a view ideas already but to make them work I need to install some plugins. I wasn't able to find plugins for all my ideas so here I am, describing them so maybe one of you can help me here.

1: There are going to be two groups. Attackers and Defenders (names are not final). Every new player will be put in one of those groups after joinging - either by choice or automatically. I guess automatically would be better so the players will be evenly distributed. Although it should be possible for me as admin to switch players from one group to the other.
I'm using Better Chat right now to make those groups but I need some way to automatically put new players into those groups. If anyone can help me here, that'd be great.

2: It should be possible to instantly recognize players by their group. If an Attacker sees a Defender, he needs to know immediately and vice versa. I was thinking about something like giving one group a specific clothing item, like the glowing eyes for example, wich they cannot unequip (it would need an extra slot tho to not be a disadvantage). But if anyone knows another or better way - or even a way to realize my idea - that'd be awesome. Maybe something like putting all players of one group into one team as well... But here I need a way to make it unpossible for players to leave said team.

3: Same goes with bases. Players are only allowed to raid bases of the other group. So they need a way to see to wich group a base belongs. My idea was to use some kind of split up map. So one group is in one half, the other group in the other half (here I would need way to block a group to build in the enemy zone).
But this comes with another problem: Players need to spawn in the right zone. It would not be helpful for an Attacker for example to spawn in the Defender's zone. I'm not sure how to solve this problem. Maybe someone got an idea here?
Also both halfs should be even in terms of monuments and all that.

4: A group chat. Players should be able to send messages only to their group so the enemy woldn't see it. I'm pretty sure I saw such a plugin already somewhere but I cannot find it. Maybe I'm just blind...

I guess that was it. If anyone knows a thing or two for one of my questions, I'd be happy!
Thanks!

If you still need help with this, I would love to try to create this plugin for you.
Contact me on Discord at HoverCatz#0060