How do i replant in Fox Farm Ocean

Hey i have a snowryder autoflower that my friend gave me in a 1/2 gal grow bag. It was planted with Fox Farm's Ocean soil. Now im going out today to buy a bag but i had a few questions about it. It seems to not hold water like normal soil, i was just wondering about this. Also when planting a new seed into it it seems very loose and all my buds plants are all falling over because they are not rooted well enough. And finnally whats the best way to replant into a 2 gal container? Just cut the bag? i dont want to ruin the roots.

Cut the roots. When you transplant make a few shallow cuts along the sides and bottoms. It's like topping the plant, except for your roots.

The meristem will branch out behind the cuts and make your root-ball thicker. Professional nursery's do this, it's better in the long run.