transplanting and root question

I've recently taken over an operation and there are a few things I'm wondering about, any advice would be greatly appreciated. I've got 45 veg plants (apprx 4 weeks) that have a very weak root system. I believe this partially may be because they were taken from rooted clones and put directly into 2 gallon pots. They were watered abut a 4 days ago and still havent completely dried out yet. I was going to let them almost dry out and them start giving them some Rhizotonic. Is that the best idea? Also, they are about a week from getting shut back into flower and I was considering transferring them to 3 gallon pots. Is that a good idea...I heard it would be better for yield if they have a bigger pot but if the roots are a bit wimpy...? The strains are Purple Kush and AK47. Thank you

Not sure what the "shut back into flower" means if the plants are only a month old. Bigger pots mean bigger roots; bigger roots mean bigger fruits.

If the roots don't go that deep, and it's been four days since the last watering, I'd give them a bit more soon. The water drains to the bottom of the pots as the "wimpy" roots are probably still in the top 4-6 inches of the soil looking for water. I'm a big fan of letting the plant work for water and nutrients, but you don't want them struggling for it. Don't soak them, but I'd give them a light watering to let the roots get any available moisture they can right now.