i would think as long as you dont touch the plant and are wearing like latex glove you should be fine and i would also think smelling the raw plant again as long as your nose doesnt touch the plant you should be ok. if your not sure you can always get a home drug test so you can see if it comes...
you may want to consider a hps for flower.my first grow was all cfls i used the 4' tubes like you.the bigger they get the more lights you will want it seemed every weekend i went to home depote for another 4 footer i drilled holes two on one side of the reflector so i could hang them for side...
400 watt hps is pretty strong for seedlings be very carefull not to burn them i would use cfl until they are 6" to 8" tall then use your hps it will save on electricity, if you use your hps for seedlings keep them far away from light like 24" or more.