You put together a good list of attributes for a jet engine. Just have to add, check the bolts and fittings twice for proper torque and I think you got it!
Then there is the matter of ratcheting up or ratcheting down. As I type this to you at 8:20 PM US EST, here is a partial listing of the airplanes flying this evening in the world:
332 B-737-800
322 B-737-700
293 A-320
274 B-757
232 B-777
213 A-319
171 B-747-400
160 B-767-300
139 CRJ-100
139 ERJ-145
120 CRJ-200
119 B737-300
71 A-340
And the list goes on to include freighters, other commuter jets and biz jets.
And finally,
9 A-380
So if you take out the B-747's and the A-340's (and the nine A-380's), the world flies on two engine aircraft very successfully. So, I would not ratchet up 4 but down 4.
As a matter of interest, think of all the fuel being used at the moment, and tomorrow, day or night it will be the same.