btw, a 2 gallon pot would be ample room for auto plant roots. they dont really get big enough to utilize 3 or more gallons, but in this case its better to be too big rather too small.
as for the spectrum of your cfl's, i would go 6500 all day man. up until you start to see buds, then obviously you want both spectrums. and if your going to flower with cfl's then i would also advise you to go to lowes and buy the work lights with the clamp and reflector. those would allow you to waste a lot less light. i dont do this because plants dont need nearly as much light in veg and i dont flower with cfls.
as for watering, just stick your finger down in the soil and feel how wet it is. i wouldnt pick it up considering its a big ass clay pot and it would probably be kinda hard to tell. if you had plastic pots then yes, you could lift them and tell. also since you have such a big pot, the soil will probably stay moist for a very long time. im sure you will water it once a week for the first 3 weeks. !!!!!!!!!(be sure to let the soil dry out a little bit between waterings in the first 3 weeks. this will help your root system grow deeper searching for moisture)!!!!!!!!! i always let my soil dry out anyways, my plants have just always seemed to like it better. they kinda thrive on dry you know