The issue here is about policy. Why not change your policy to always have a spare computer on hand and ready to go? Then if someone's computer dies, you overnight it and they are back up and running.

My comments:
1) Users will use whatever equipment they can get their hands on, meaning that any spare equipment that is laying around will be commandeered for some other purpose. Also, unless each of your sites has a large user base, this may not be very cost-effective.
2) This is great for metropolitan areas, not so easy for the heartland and rural communities.
3) Same as #1 and #2. You have to have a "critical mass" of users to justify local support, and part-time help in IT is almost worse than no help. This one is a real challenge for businesses with lots of small remote offices to manage.
4) This one is a huge time/money saver. Most users can't fix their own problems and are only marginally good at following directions to fix a problem. Being able to quickly get on and fix the problem is key.
5) This is an easy trap to get into because you don't have to see that person every day. But how many help desk technicians really do this? IT support is all about consistency. It takes a conscious effort to be nice/helpful to some people and not to others on a given day.