I am not Disagreeing with most of your advice Oldreefer, but I have to say that planting in the main container with no transplant will help them out, even though they might not show signs of stunting right away if transplanted. If you study the root formation of autos you can see why... Most autos out there start by putting down a very long taproot, sometimes up to 15 inches down if it has the space. This is why it is advisable to get tall pots instead of wide ones (party cup profile is a good shape) with autos. Of course there is the party cup method, and depending if you're using soil or hydro with controlled powerful light, you will get a great yield (up to 3/4 of an ounce in one main bud on a stick) for such a small area but as Oldreefer said, it's definitely harder to keep the moisture right all the time unless you are using hydro. I have seen a Lowryder plant produce as little as a half a gram in a large container because the roots bound up so quickly before transplant compared to Photoperiod plants. The main thing to remember is that autos have very vigorous growth, up to 3 or 4 more times as much as photoperiods! This in mind, transplanting can be done successfully, but needs to be done quickly after germination so the long taproot has somewhere to go...
Growing autos outside will surely require larger pots so as not to impede growth, I have taken Lowryder #2 outside in a 2.5 gallon pot for germination, and seen them bust the max height set by the seed breeder before they even start flowering! I'm talking 16 inches when the first pistils make their appearance! This is a plant that supposedly maxes out at 20 inches in rare circumstances at maturity... by the time they were done they were all around 25-30 inches and one of them produced over 2.5 ounces!
Good luck and happy growing!