I've ran ceramic rings for years on my filters, which i think bio max is too? Anyways, never have i had any clogging issues people talk about. Bio-film buildup to that degree is usually the result of letting biofilm build up which takes a food source per say, which is usually over stocking, under filtration, or not proper weekly maintenance, or a combination of them. You dont specifically need water flow through it, just around it which any filter will obviously do. The whole thing is porous, not just the center. I also use matrix, it's a great bio media, but i also use sponge as well.
I find sponge tends to pore clog more easily, and you should every month squeeze them in and shake in treated water. I love it though like all my biomedia. Having several media's is always better then one.
Having more fish will depend all on the tank size, species kept, and lastly filtration yes.
I'm not into the image, but into the hobby...