Is it ok to have the fermenters raised/positioned above or higher than the Glycol Chiller?
Yes, you can have the fermenters on a shelf higher than the Glycol Chiller. As long as the fermenter is no higher than 30cm (12in) above the chiller, the pump will work fine.
Do not sit the fermenter on the Glycol Chiller. The weight of the fermenter will damage the chiller. Also, if the fermenter leaks, this could damage the electrics in the Glycol Chiller.
Is it ok to have the Glycol Chiller raised/positioned above or higher than the fermenters?
Yes, you can have the Glycol Chiller above the fermenter. As long as it doesn't obstruct the hoses or the lid of the fermenter, this will be fine.
Is it safe to unmount the wheels and let the chiller rest on the plastic frame?
Yes, you can unmount the wheels and rest the chiller on the plastic frame.