Bartian’s remarks on shyness are entirely correct. It depends.
Very experienced breeders (see http://www.guenter-kopic.de) make sure that their tanks are not placed within very light rooms. They cover the back and side glasses with black paper. The inner parts of the tank must be the parts with the most light, not the room outside. Then you will see you fish and they will not be shy.
It’s a marked difference with P. sumatranus. Interestingly, all breeders of this species report on its shyness. Mine were always very shy.
Cryptocoryne: We need the names, Bartian, and that is: the correct names. The normal aquarium species are species from Sri Lanka (Ceylon), such as wendtii, willisii, “nevillii”, beckettii, or undulata. The C. wendtii is the most-traded Cryptocoryne in many variants (broad leaves, narrow leaves, green, brown, speckled etc.). They are hard and to cultivate submersed in aquaria without severe problems. Nearly all species from the homelands of our Parosphromenus are difficult to cultivate submersed (not: affinis, but affinis will not do in soft water!).
Peat: Of course there is peat without any fertilizers. But you must be very conscious about that. Most peat for gardeners is sold contaminated with fertilizers. That is useless or poisonous for our purposes, of course. But you can buy pure peat.