the combination Generator Air compressor & vacuum pump sounds interesting
also quite doable the one obstetrical to overcome would be voltage and HZ stability when the compressor was pumping to do this obviously the engine would need to be sized large enough to handle full load of both without significant RPM fluctuation the AVR in most inverter style generators can can do a pretty good job of maintaining stable pure sine but until you get in the 25 and above KW range the engines are sized too close to the HP requirements of the generator to handle the added power requirements of an air compressor of any significant size. if you need it to be able to run something like a 3/4" impact wrench
if you are only needing to power your house in case of an emergency then a a small 8 KW generator with a 2 cylinder diesel would be sufficient the engine could be adjusted for an additional 3 to 6 HP without long term harm to the engine and a compressor head from a 6 HP portable gas drive compressor could be belt driven the unloader valve would take care of cutting out the compressor when the storage tank is full.
a vacuum pump from a Ford 7.3 IDI engine with a small 1 gallon tank would handle things like pulling a vacuum on refrigeration and air conditioning systems
B for the recliner combo scout used air craft auctions for the fold down arm rest furniture from the business & first class seats of many airlines you can get them in both left and right side configurations attach them to a lazy-boy then re upholster to suit