when using analog input the front panel LEDs show the Eventide input headroom. This is about +26 dB (HUGE) so you don't really need to lit them up close to the top. 4 or 5 LEDs are ok.
When using digital input the LEDs work in a more traditional way, indicating 0dB headroom at the top LED.
Some presets (distortion/gain fx) also use a GATE. You may need to adjust the gate parameters to fit to input dynamics to correctly use these presets.
I have never seen gaintrims being not functional. Try a CLEAR SETUP:power on the unit, when you see DSP7000 on the display press & hold the SETUP key. Then press the YES key on prompt. this will reinitialize the settings under SETUP and LEVELs to factory default. This doesn't erase your presets …but having a backup is always a smart measure.
Let me know if it worked!