I have never tried to cross pollinate VFTs. I take it when it comes to growing VFTs from seeds it is a craps shoot on the traps the seedlings will take on? Also, is it correct that seeds from a 'Sawtooth'/'Red Piranha' will most likely not have the same traits as the parent plant? I have only propagated VFTs from leaf pullings and flower stalks.
Yes, with pollen and seeds, even if one pollinates the flowers of a plant with pollen from the same plant, the resulting seeds will produce a wide variety of offspring, so the resulting seedlings may not have the desired characteristics of the parents. Since I hand-pollinate all the flowers on my seed-producing plants I consciously try to make interesting cross-pollinations, but it's a pure gamble and a mystery what types of little plants will grow from all those mixtures of genetics.
With Venus Flytraps we're constrained to just a single species, Dionaea muscipula
, unlike the vast genetic differences in inter-species breeding or even inter-generic breeding such as occurs with many orchids. Those can produce some really wild-looking offspring! But with Dionaea all we can do is to try to encourage and incorporate into breeding experiments the more interesting genetic results that occur. It's kind of fun though.