Question

no

vege length = size of plant and not much else. So, it's only early if it results in a plant smaller than you intended. people usually say expect 2-3x the growth after flip, but the longer the vege the bigger potential for growth after flip to 12/12. Growth early on is a curve with an increasing slope (essentially exponential initially). Pot size can put a cap on potential size long before any limitations on size outdoors in the ground. With six+ weeks and a robust plant, expect 3x growth.

Depends on your goals. You can go 12-12 from seed if you want. 6 weeks of veg can be vastly different depending on environment and strain. Most people veg until they have got the plant both healthy and have built the canopy to the point they want. No point flipping if your plant is going to get major deficiencies during the high demand of the first few weeks of flower, nor if there is not enough plant to make the time, nutrients, electricity, and effort not worth it. Hopefully that tid bit of info helps you make a slightly better informed decision. Good luck, and happy growing.

6 week is fine if you have filled your area out.

No.

Nope , flip it when you want to

I flipped my Ghost train hazes at that point. Had no issues.

Anytime after 3 weeks is OK. You can flip right from seed but it won't flower for at least 3 weeks until established. All in all, the veg cannabis growth stage typically lasts anywhere from 4-8 weeks. But just because a plant can go into flowering at 4 weeks – doesn’t necessarily mean it should. By doing so you can risk growing a smaller plant than originally intended. There is no right or wrong.