'sup whispers, and welcome.

Here's the deal with repotting vs seeds in one pot the whole grow:
There's a couple big things to think about.

1- SOIL. The seedlings need a much gentler, nute-poor soil for the first couple weeks of life so they don't burn. Then they need a veg soil, that has nice organic sources of N, like blood meal or fish glop. Then after that, they would like a soil that has lots of P in it, like from bone meal.
2- LIGHT. The efficiency of your grow is largely dependent upon not losing any light to the soil... ie, having a continuous canopy. So your little seedlings should be all crowded together under a few CFLs... then when they get bigger, you can put them in bigger pots and crowd them again under your veg lamp. Then you see where this is going, as they grow bushy and ready for flower, THEN you want to stick them in the big assed flower pot under the big assed light!
3-ROOTS. It is actually kind of good to let your plant get just to the EDGE of where it is rootbound... then you transplant it, give it some vitamin B1-thiamine, and BOOM it will grow before your eyes as a thank you for a nice new home.

The myth of transplant shock.... if you grow in nice smooth-sided, clean plastic containers it IS a myth! Just make sure you are always gentle when you handle your babies and they will not suffer any shock at all.