Well, Ray you certainly know what you want and I see a lot of merit in your wish-list of what not to have. One compromise, however, may be to consider a vehicle that does have 4WD; there are vehicles with 4WD systems that are very passive and work only when wheel slip is detected - like on gravel or mud.
Maintenance is virtually nil and there is little penalty for the extra weight. Nice-to-have especially for towing. On that subject you don't say what you intend to tow so I am taking a punt on a braked load of around 1200-1500kg.
The budget:
$12,000-$15,000
The shortlist:
Nissan X-Trail
This will tow up to around 1800kg (2.4 litre engine) for a braked trailer (750kg un-braked). It will also provide the height for ease of entry and exit you want as well as the space for a wheelchair. It's a no frills, reliable, practical and easy to maintain vehicle that offers great value for money as a used vehicle. No cambelt, either.
Toyota Corolla
The trusty, bullet-proof Corolla station wagon may appeal. It virtually covers all your requirements although it may lack the high ground clearance you seek. Towing may also have its limitations with anything more than the garden trailer a struggle. A New Zealand-new 1.8 litre example would be the one to go for.
Suzuki SX4 Hatch
Another vehicle that flies under the radar for those looking for a good all-round package that fits within your budget. Suzuki NZ staff tell me it's good for up to 1200kg with a braked trailer (600kg unbraked) with either the 2-litre or 1.- litre engine. The rear seats may have to be checked for wheelchair accessibility. The SX4 is sold as a 2WD only or with Suzuki's on-demand AWD system.
Driven recommends:
The X-TRAIL especially if you have the need to tow on a regular basis, but remember, towing recommendations are based on a manufacturers approved towbar being fitted.
For car advice email driven@apn.co.nz