The crankcase gases are bad for your throttle body and motor.
Crankcase gases don't pass through your throttle body unless there is a major problem with your piston rings or valve seals. The tube in front of the TB is a breather line, it just lets filtered air replace air the PCV draws. You can replace this with a standalone breather filter with zero impact.
The crankcase vapors came from inside the motor anyways. They are a mixture of fuel & oil vapors. In other words, gas and upper cylinder lubricant. On today's GDI engines this PCV material will accumulate on/around valves and cause engine problems. The EFI 2.3 does not have this problem as gasoline is a solvent and when injected indirectly it washes down the valves and intake port as it goes in.
Venting them to the outside via breather removes the vacuum thereby leaving some gases in place and allowing backbressure on the movement of internal parts ie pistons etc.
Engines will create pressure internally if not vented properly, yes - this pushes oil out of your seals. Even brand new gaskets. You'll have a really bad leaker. Even the best catch cans back in the day still covered old motors in oil which can be harder on other things in your engine bay. PCV vac is about 1-2PSI.
At full RPM on an engine with significant blowby (which isn't gonna make you power anyways) crankcase gases will blow out the breather tube on the top of the engine. Greases out your engine bay pretty bad.
In short PCV solves a lot of problems and removing it won't get you anywhere special. It affects AFR slightly at all RPMs. Even with a fuel map or a canned tune installed your computer still may be accounting for it in its calculation of intake air. I'd keep it.
Would there be any benefit to me for my specific application in removing my cat?
Yes, in a way. The original factory cat is bulletproof, HEAVY, and pretty restrictive compared to modern cats. A 2.5" Eastern Catalytic Eco-II unit feels like it weighs half as much. There is a lot more benefit in moving to 2.5" cat + cat-back exhaust. Especially if you have the factory shorty header.
Personally I like to run cats but don't care if others do. I have a dog that rides in back, he doesn't need to breathe that stuff. Second, every riced out Honda or Subaru I've ever driven behind has not run cats and the smell seems to offend regular folk in the city.