I much prefer direct sowing into pots rather than messing with starting indoors and moving them later and having to harden them off. Cannabis is a tough little plant and if you are worried about animals some mesh covering the pot can help.
With a tiny autoflowering plant like lowryder you want them to grow as fast as possible to get as much yield as possible and the key to that is too keep them growing as strongly as possibly . Transplanting and hardening off both reduce the growth rate (no big deal with plants that have a long period of vegetative growth) and that will mean less bud on any autoflowerer. Three gallon pots sound about right to me.
Good luck
Slart