you can veg them for as long as you like bud.....the longer you veg the more you will get from your yield. plants can be flowered as soon as the plant has reached maturity, ie when calyx's hve appeared by the node joins (the white hairs). During flowering the plant will grow up to 2-3x the size so it depends on your height restrictions but our plants are looking good atm, as for touching the sides i wouldnt recommend it as the leaves wont be getting the light penetration they need. what you can do it make small ties and make the branches sit more upright by tying them to the nessessary amount.
peace
My oldest plant is at 5 weeks and 1 day of vegging so 36 days. The other ones like a week and a half younger. Heres some pictures of them. I'm wondering if I could veg them for another 50 or so days. one of thems already pushing up on all sides of the closet, will it be ok and just continue to grow up instead of out further? thanks 
