A 2000 with only 84K? wow
For your front seal I'd try a bottle of auto-rx. It will not fix a mechanical problem but it will clean up any gunk that maybe impeding it effectiveness. It may also clear up your CEL but I would get those read anyway at a local auto parts and see what they are. It could be something very simply or......
Oil lines, I'd look under the vehicle and see exactly where it leaking before I go spending any money. It shouldn't be to bad of a job to replace, sounds like a DIY.
www.auto-rx.com