Alright Bill, just needed to give ya the newbie intro.
1) Alternator deactivation
This has been covered a few times. You can search for 'atlernator delete' or 'alternator disable' to find pertinent info. Controlling it with a microcontroller is an option, or use a voltage comparator chip to measure tps and battery voltages. However, if you are going to keep the alternator disconnected for any reasonable amount of time (giving the best mileage increase) you're going to need a deep cycle battery. Then, I'd just size it for your daily commuting so you can keep it off all the time. If you want to do something fancy, engage it when you brake. I considered this when I did my alternator disable, but have decided there are just better things to pursue.
2) Electric drive
There is so much flexibility with this idea and tons of options. You need to decide how much power you want/need and then decide weather you want to go with AC or DC. AC will give you regen but controllers and the usual voltages the motors require is quite high which means a lot of cash.
One guy here has done a conversion like this.
Geo Metro plug-in parallel hybrid EV - in progress
3) Auto start/stop
This is quite doable, although nobody here has done it either. A bit of work with a microcontroller and using the ABS sensors and tps of course would probably give you want you want.