I have a 2003 disco non secondary air that has LTFT -12 on both banks all the time and short term all over the place it also cranks at high rpms on cold start 1700rpm and used a quart of oil over 3000 miles any advice.

 

The quart of oil could be going anywhere. The rest of it I would just keep doing maintenance and drive it until something breaks. You can try cleaning your IACV and replacing your MAF sensor, but if it's not throwing codes there's no real reason to start buying parts.