Oil on the rammer after a day of play.
Lube the lpr and the hpr after 10 cases or so. IE Monkey Poo, Hater Sauce, Sl33k.
Etek's are pretty idiot proof it does not take a whole lot a maintaince to keep them going.
Try a LITTLE amount of blue locktite on the problem screw. Once you set it as you like it let it dry for a few minutes. As for the macroline, if it is not cut properly or seated all the way they will pop off, just make sure the cut is straight and give the macroline a tug when when you install it.
The basics man, make sure they keep their goggles on when they get shot out, and put their barrel plugs in when they leave the play area. Also treat them with a light touch but keep stressing safety to them all day. Keep the older more experienced kids from overshoting and bunkering them too much.