What if I put the germinated seed right to a big p...

One more thing, each seeds will not grow exactly alike. There will be some good plant and some dwarf. It is difficult to see from the start. Best not to waste soil and effort on runts that won't grow.

I think it is a waste of fertilizer. Water washes off fertilizer in the soil. And the soil may compact before root grows. I chase pot size up. I haven't notice any "transplant shock". Trick is to let soil dry before transplant. Then the old pot comes out easily enough without root damage. My usual pot sizes steps are 300 CC , 2 -iters, 7-liters, 25-liters, then final pot between 40-liters for fast flowering type to 80-liters for four months Sativa flowering period.

You can do it no problem. You can run into issues if you over water. Best of luck on your grows.

It is always best to start in peat pellets or rockwool and let the roots break through before planting in soil. Amended soils are to heavily ferted for newborns and they can suffer. With the roots already developed they will be more apt to take the heavier nutes in the soil. So if I was going to plant directly into the soil I would plant the peat pellet in there as well and plant the seed into the peat.

It will grow still. Some people just think its easier to get the roots to the edge of the pot when you gradually move up.