I don't hear a racheting noise,what I hear is the sound of the center pickup rollers clikety-clack over the joints in the track, totally normal. Cherry switch clicking is more rythmic in nature and will coincide with chuff sound and smoke puffs, some cherry switch clicking is normal as well and is usually not easily heard over the sounds when they are up. Outside of that, loco sounds nice and quiet. A diesel doesn't have a cherry switch so if you hearing a similar clicking from your diesel, its likely from the diesel pickup rollers. Get your eyes down near the track and stare at the joints as the loco passes over it.
As far as the smoke unit fan noise, some tend to be louder than others. Lionel has seem to had a "batch" of fan motors of late that have been noisey or don't work altogether.
If it gets worse or stops blowing you'll probably want to send it in to be repaired under warranty. If a smoke unit fan quits you'll get a repetative 3 flashes of the cab interior light confirming this. Assuming you purchased this stuff new VL locos have a 2 year warranty so you'll have plenty of time for coverage if you need it.
Good luck on the new layout Biggs!