Okay. Its great you are trying to do some research before you buy. Too many people go ahead and do things without researching about it first. There are numerous things that I need to say.... firstly is gonna be this:
There is no way you can keep Lake Malawi cichlids in a 10 gallon tank. They need AT THE VERY LEAST a 30 gallon tank, and that is just for the smallest most docile fish. I reccommend a 55 gallon to anyone starting with malawi cichlids, and most likely they'll still be upgrading in the future depending on which species they will keep.
So if you are still interested in Malawi cichlids and are going to be getting a bigger tank (30+ gallons) then read on.... (Also if this is just gonna be a fry tank thats okay... fry can be kept depending on how many and the species in a 10 gallon until they are about 3/4-1 inch).
You cant rinse flourite before adding it to your tank... it says right on the package not to do that. Your rinsing away needed nurients within the substrate. Rinsing is not required. Also, you cant mix flourite. Its to be used on its own as the only substrate (and about 1.5-2 inches of it). On top of that even if you did mix it crushed coral is the worst substrate to mix it with because many species of plants cannot handle a high ph, which is caused by the crushed coral. Laterite is meant to lower pH to neutral which is now being negated by the crushed coral.
There are very few plants that can be used in Malawi Cichlid tanks because the cichlids eat the plants. There are three species or genus of plants i use: Anubias, Vallisneria, and Java Fern (dont know the sci name). Even the succsess with these plants is varied, but I've been able to keep them flourishing in my african tanks.
If you cant afford to buy a larger tank then your gonna have to scrap the idea of keep lake malawi cichlids. You could try some Lake Tangynika shelldwellers, but I didnt have any success with them in a 10 gallon. The male killed off all his females. They are small enough though, so maybe try a pair (1 male 1 female). With these guys you could keep more plants, but only plants that will be able to handle the high pH that these fish need, and your crushed coral is gonna create.
Or you could do a planted tank, and get all new substrate of just plain laterite.

Hope That Helped...
-Diana (Oops... This is ~*LuvMyKribs*~, I posted as Raf

).