You may have misunderstood my earlier comments concerning the heat. I wasn't just meaning you had to heat the tank; my point was that the blue ram must have warmer water than many other tropical fish species, and species that prefer less warm water will be less healthy in water that is warmer.
Fish are ectothermic, meaning they cannot regulate their internal body temperature; they rely on the temperature of the water. So temperature drives the fish's metabolism, which means that their internal physiological processes will function according to the temperature. The higher the water temperature, the more energy the fish uses and the harder it works just to maintain its normal body functions. Continuously, this wears the fish out, they become weakened, the immune system begins to fail, and the fish will eventually die prematurely. The point of all this is that temperature is thus extremely important for fish health.
As an example, if you get blue rams, they will need the tank kept at no less than 80F (27C). IF you were to put neon tetra in with these rams, the neons (which function best at cooler temperatures) would find this warmth debilitating and weaken. In reverse, if you keep the tank around 75F (24C) to suit the neons, the blue rams would find this too cool and they would weaken.
Maybe. Rams of both species feed off the substrate so they could be simply sifting through the sand to look for food. If however they are making shallow circular craters or pits with their bodies, they may well be close to spawning.