hi, you humidity dosent sound to bad, but you certainly dont want it to rise above what you already have,

i dont belive theres any such thing as vegging for to long, as long as your space can accomodate it.

your grow sounds simmilar to mine in a few respects, i used a few methods for reducing the bulk of the leaf mass, one being using a plastic zip-tie about 1/3 up from the soil of plant height, to pull some selected good yielding branches, it also saves space with the side growth and stop it flopping out.
also, i removed probably 1/2/3 branches on each plant on average to maximise the stronger branches.