Some good points in your post. There needs to be a balance in the server in terms of being able to PK relatively quickly, but also having incentives for people to grind things out for a sense of achievement. Currently, the economy has a large surplus of items coming in from boss drops. This is reflected in the massive price drops in popular items. I think the best way to tackle the issue is to remove coin drops, remove additional player drops from bosses, reset the economy, create more cash sinks in the form of degradable armour and weapons/, skills that require items, other incentives (alternate spawns/alternate teleports that allow access to restricted areas etc.) and so on. Combat exp should not be changed as there's no point in doing so. Boss pets, new bosses, new mini games, and things like achievement diaries could add new aspects to the game that would keep it fresh.
Wrote this on my phone so it might be half-assed. Will post more later.
