I would not worry about your Nemox, its a fine machine in its various guises and badges.
The important think is that the machine has the power to pump through enough water to produce 60 mls of coffee in 30 seconds. As most vibtatory pumps are made by the same Italian manufacturer (Ulka), that should not be a problem.
(Just by the way: Ive seen more powerful Chinese pumps on very cheap machines)
The group head should not leak. Nothing should leak. The drip tray is to catch stray water from flushing, portafilter jiggling, backflushing etc. so theres no mess on the bench.
You say you got sprayed when you tried to re-prime your original machine --- that can happen when the boiler is very hot and under pressure with steam. The steam pressure sprays out water from the group with much force and can scald if you are not careful. Ouch.