the one in the middle is a Dracaena, i believe D. sanderiana, but im not sure. its not an aquatic plant, and it will die pretty quickly underwater. my grandmother actually grows them in a dry pot in her living room. i have no idea why so many stores rip people off like that.
any pice of a plant that has both roots and leaves can be separated out from the rest and planted as an individual. you'll see that your great big cryptocoryne isnt a great big cryptocoryne, but a whole bunch of much smaller individuals. you can spread them out a lot from where they are now - it look likes you have at least twenty individuals. anubias can be split up similarly, but i wouldnt recommend it. you can cut the rhizome into as many pieces as you want, but as long as each piece has a leaf on it, it *should* still grow. the fewer the leaves, the smaller any new growth will be, so i would advise not chopping up anubias into pieces with less than 5 or 6 leaves.
the dracaena will not branch, and you cannot cut it into any pieces that will survive. get it out of your aquarium and find a nice new big red ceramic home for it!
as for the airstones, etc, you don't need them. air stones are for when you have big fish in small tanks, or when you want more O2 in the water for some reason. in fact, you want less O2 and more CO2 in the water, so the air pumps are actually making it harder for your plants to 'breathe,' so i would also turn those off.
as for the cloudiness, its just part of setting up a new tank. it should go away in a few more days, or a week or two if you have a really dusty substrate. anyway, don't worry about it.
as for fertilizers, you won't need any water column fertilizers. those are for stem plants that take a lot of nutrients out of the water. crypts mostly take nutrients in with their roots, so you may need a root-fertilizer eventually. these can often be found in the form of "root-tabs" or various sticks or tablets you put in the sand underneath the plants. they should be fine for a while though, so i wouldnt worry about it. fertilizers are usually for "high-tech" tanks with multiples of the amount of light that you have over your tank.
for now, you should stick to plants that need very little light, like anubias, java ferns, and crypts. here is a website called Plant Geek
that will show you all of the fake aquatic plants like Dracaena that will die, rot, and pollute your tank, and the low-light plants like anubias and java fern that you will be able to keep without any problem. its a handy resource!