If the frogs are similar in size it should be fine but if ones head is more than 1/4 larger, you might end up with just one tree frog. Monitor their weight and make sure one isn't getting skinny. If this happens, you can tong feed the skinny one it's food until it puts on size. I wouldn't remove the frogs for feeding, just feed at night when they are active and the crickets should be taken fast enough.

Vitamins should be given at the same time as calcium as they work together and insects should always be dusted or gutloaded every time they are fed out because commercial insects are high in phosphorus and poor in calcium. However, the problem is many supplements can be high in the fat soluables such as A & D and can cause problems when used regularly. I use Repashy calcium plus for this reason as it has been designed for daily use and there are options of low, medium and high in regards to vitamins.

I would swap out the superworms for nightcrawlers and roaches every few feedings because these are much more healthier and superworms are fatty. Tong feed the roaches because they will burrow.