I will write the ideas in order of priority:

1) Of course we need new servers. I assume that you have not changed them for 15 years and it is very problematic to play without nerves. If you don't solve this problem making other edits is practically useless. We old players know about this problem and used to but if you are counting on new players joining us it will scare them.
2) We need a system of local events: create a set of ~ 10 pieces and let the server runs them at random in a random place in the location notifying all the players in the chat and creating a special area-hint on the map. I do not think that everyone is so important that this will be the event, so you can use the classic scheme of PVE:

- Monster players can be given an event to steal one of the NPCs in the free peoples castle. He will need to get to his fortress as quickly as possible, any.
- And the free peoples to give the reverse event: NPC himself escaped from one of the fortresses and need to bring it to the nearest allied fortress.
- Caravan: several NPCs with horses and free peoples supplies can deliver food from one fortress / Glân Vraig to another place and they will need to be protected on one side and vice versa try to disrupt delivery on the other side.

You can think of many such events, but I think the point is clear: to create additional clashes between players. The main problem - we do not know how many people will be at the event, it will be a raid of 20 people, or come just 1 player so it is difficult to balance them - so I would suggest running both events and label them for clarity: One small event for a group < 3 people, and the second large event for a group > 6 people. Ideally I would do area restriction: you have a dynamic layer system, if you can adapt it and divide players into groups with it that would be great.

3) The current situation is that for many years now PvMP is mostly designed for group battles, but as a player with 11 years of experience I remember a long time ago SOLO / DUO battles flourished because there were so many players running around the location without a group and it was awesome so I would think about solving this problem too. Partially it can be solved by the previous point with the creation of events for a small number of players, but the rest of the time the problem will remain relevant. I will propose my version but if you think carefully I'm sure others will find solutions not worse or even better: to encourage players to play without a group or in a small group of 2-3 people you can do scaling points a player gets for killing a player - it's easy if you're not in a group and playing solo you get for example 30% more points than he would have been with someone in a group together. If there are two of you in a group you get 10% more points than if there were three of you... I think the point is clear: penalties and bonuses depending on the number of players in the group. This is a controversial decision and can scare the group players I understand and do not insist on this solution, but I, like not a few other players saddened by the lack of opportunities to play yourself because the group of 6 + people will kill you at the first opportunity. Maybe better to do the penalty if it happens: check if there are no other players in the radius - if not then the group will not get any points at all, or even minus for killing you in a crowd. This is a tricky topic here, you need a lot of other opinions and thoughts.