Ok, well they wont do it all the time, keep an eye on the eggs, if they start to look fungusy then take them out because they are either not fertilized or they are dead eggs.
Not necessarily, some do, some dont. Its usually infertile eggs that go fungusy. So you may get some which didnt get fertilised next to some which did.
You can I think if you were to remove the eggs and put them in a tank on their own, but I wouldnt with the rams in with them, they should do a good enough job fanning them which should help prevent any of them going fungusy.
It helps, but as I said the parents fanning the eggs will be fine. The only time you would need extra aeration would be if the eggs were removed, then you would use an airstone to create the fanning process.