looks good,i wouldnt worry about the minor burn,it could be from the guano,but like dr says if it gets too extreme then flush.
next time u should grow one girl and top and fim her to the maxx. and use a closer nitted screen and dont cut holes out for the plant to come through,let the plant find the hole and work itself through,then top or fim the sites and put another screen ontop,layer a few screens,u know what im saying?
after you are happy with the way they are movein through then flower,but u need to cut any veggetation that is not goin to be usefull, basicly expose the stems to get good air circulation and to become thick. i would do this for your next grow,not now bc it could shock the girls and focefully make them herm through stress