Hi again; I woke up today with a new perspective on this problem. Here's a test you can do that will provide valuable information. Make sure that all electrical accessories are turned off, the key is not in the ignition, and close all doors. Then disconnect the battery ground cable and let it sit for at least 2 full minutes. Then briefly touch the battery ground cable clamp to the battery post from which it was disconnected. Watch for a spark when the cable clamp touches the post. If there is a spark when the cable clamp touches the post, then do not connect the cable. Instead, leave the cable off and disconnect the heavy power cable at the alternator. Wrap the alternator cable end in a rag, or cover the metal terminal on the end with electrical tape, so it cannot touch ground. Then try touching the battery ground cable to its post again, and see if there is a spark this time.
If there is no spark when the battery ground cable touches its post this time; the alternator has a shorted diode. If there still is a spark this time; there is a short in the car's electrical system.
Either a shorted alternator diode or a short in the electrical system will drain the battery when the car sits. This is why the car won't start after it has been sitting. When you disconnect the battery for two hours or more, the battery has time to recover enough to have sufficent power to start the motor easily.
If the alternator has a shorted diode, please only buy a replacement alternator at a NAPA parts store. The reason for this is that most other parts stores sell cheaply rebuilt alternators which are not properly tested and often contain questionable used parts taken from other old alternators. There is a massive failure rate on these "rebuilt" alternators, which often leads to getting two or three defective units in a row from the store. NAPA is the only local place I know of that still properly rebuilds and tests their electrical parts.
Alternator diodes will blow out immediately if a battery cable is ever disconnected while the motor is running. There is an old myth that an alternator can be tested by doing this; but that was only safe to do 50 years ago; when cars still had DC generators. Modern alternators produce enough power at idle that they will build up 150 volts or more when a battery cable is disconnected; the diodes can only withstand about 50 volts, so they blow when that is done.
If there is still a spark when the test is done with the alternator cable disconnected; you'll need to pull all the fuses and relays, one at a time, from the underhood and under dash fuse blocks; and test for spark at the battery ground cable after each one is pulled. Put each fuse back where it came from before pulling the next one. When there is no spark in the test; you have found the circuit where the drain is coming from.