yeah for sure.. mite see the plants start to stretch more than usual but yes its ok to veg with 2700. MH will be much better for node growth and keeping the plants a lil more stout so maybe think about grabin one up in the future.
Yes you can do it. Remember soft white bulbs are for vegging and warm white is to flower. Having a combo of 80% warm white and 20% soft white during flowering can help slow down stretching and have nicer buds.