yea seems like most have been said ..
tho I like to run my Veg time 20/4 (some even run it 24/7) the more light time the more growth .. so to speak ..
but also more stress on the plant and gear and more power used .. so your choise ..
evrything over 13 hours will work .. as the plant from natures side (unless its a Auto strain) have addapted to the light cyclus and will begin to flower once fall is comming (less the 13 hours days)
witch also kind a answering your last question .. the longer veg time/spring/summer = the bigger plant = bigger yield in general
what we do inside is just to try to copy nature .. nature when its optimal for the plant we grow (27C/50% RH .. windy .. with good air/co2 exchange)
Ooh yea and last .. about repotting or moveing them to bigger pots .. I do it .. I start mine in cups (if you choose big pots here your in danger of over watering and haveing a wet bottom in the pot all the time witch weed dont like .. they like airy light soil with good drain)
when they are around 2-3 weeks old have a bigger root net and is`t seedlings anymore they are mostly ready for a bigger pot (I use 3 gallon) I mix my own soil so I also mix it specific for veg. here ..
I keep em in them for like 3-4 weeks untill they are mature and I feel they soon are ready for flowering then I repot in to the final pot (5 gallon) and do the pruning and last LSTing .. give em a few more days then switch to 12/12
a few things that do .. fist of all weed like to spread ther roots out to the side .. so if you start in the final big pot the plant wont use like 30% of the middel of the pot so to speak .. if you let it start in cups/smaller pots it will develop nice big root nets that will fill out the middel of the final pot .. witch will help the plant take up water/nutriens and will give a better yeild in the end (from my experience)
and as I said before ..
a small plant in a big pot might only need water every week ..so it might stand in wet soil for to long ..
I like to keep em in pots i have to water evry seccon or tird day ..
if it just run through and feel dry and crispy and you have to water evry day .. your mostlikely rootbound and need to repot ..
that is also why I like to do it just before 12/12 .. so I dont end up making a repot in flowering ... agin
(that will stress the plant more then I like)