Yes, outputs are unbalanced. Rec out filtering uses a brew of active and passive filters that includes LPF, HPF, and BPF. The bode frequency plot isn't so cut and dry where specifics would be very meaningful. The most noticeable effect is on a reduced HF sizzle, but it reigns in the bandwidth on both sides to approach the bandwidth limitations of real speaker and microphones, etc... It is crude, but useful for those who want to go direct with a distorted sound but get around that industrial sizzle sound that typically comes with direct distorted sound.
EQ is similar to the type found in most classic amplifiers, the 3 band tone stack which has interactive behavior. The symbols are a misnomer that stuck from our early days when the simplicity of those eq symbols was a good solution to home screenprinting each individual symbol

Engineer guys will know that it's wrong, but it stuck all the same.