Engine Catch Can or not?

IMO--No. EGR is the biggest crud builder on these cars, if you want to keep the intake clean delete that.

Make sure your PCV system is operating correctly and use a smoke machine (bought or DIY) and check for vacuum leaks.

As aero suggested, make sure the entire vacuum system is in good shape.
Doesn't sound like you daily drive it, personally i wouldn't worry about it too much. Even with a catch can some oil is going to get in there. Not to mention in general it wasn't a big problem like it is on newer cars.

I'm running an Expo lower with the large baffle and no EGR. Intake stays very clean.

Car uses about 1/2qt per 5k miles. No leaks.

Catch cans are most beneficial on newer cars with direct injection. On a 5.0 Foxbody? , meh….pass

Catch can systems can be beneficial, regardless of fuel delivery system - for street driven vehicles. Regardless of engine, the PCV system collects oil vapor and that oil vapor travels back into the induction tract of the engine and gets consumed in the combustion process. Some engines, certain direct injected engines for example, are more prone to issues caused by this. This can cause buildup inside the induction system and on the valves etc.

It's all relative to type of induction, engine, how it's driven etc etc.

Does it have a noticeable impact on most engines, unless your are talking long-term / high miles situations? Doubtful.

Same with EGR. I've removed my fair share of these systems, especially older designs, but a correctly working EGR system doesn't really hurt performance. Some tuners even lean towards it helping in certain situations as if it's working correctly it can lower combustion temps. This is more beneficial with forced induction, being able to run higher static compression ratios and more timing etc.

Just my 2 cents and what I've seen over the past 35 years of throwing wrenches across the room and wishing my hobby was cheaper.