Agreed that 3 years isn't a long time, especially if you haven't been racking up the miles, but suspension joints are sometimes not as good as they used to be. Worth checking them all. Maybe the outer lower one which isn't easy to check, being under load. For the rattle, possibly the anti-roll bar bushes or mounts to chassis cross member?
If your brakes are decent with no pulling to one side, I'd leave them until you're sure the suspension is OK.