the Arcade mode will open for a preset that was saved in Arcade mode. Arcade or simulation are actually a type of preset. You can't disable that, try to find presets that were done in Simulation mode. Or are you saying that EVERY preset opens in Arcade mode?
Another issue I have is if I select a preset the preamp is always on meaning there is a huge increase in volume. Can this be turned off to by default?
You probably meant the POWER AMP is on, again it depends on how the preset was saved, if it is saved with a PA on, well, the PA will be on next time you open the preset.
All of that means you probably have to do your own selection of presets where you switch off the PA and save in Simulation mode.