Can't tell you about the fit of the new cleaner, but if they sell it there's a good likelihood that it's low enough profile to work. The problem is, and the reason stock ones are offset, is that there isn't much hood clearance.
As to whether you can remove the stuff, no you can't remove all of it. You can use alternates for most of it, but you want to keep the function of your PCV valve, which is the hose on the passenger side rear that comes from the valve cover elbow fitting up to the air cleaner housing under the middle section.
The second one is the charcoal canister hose that fits over on the passenger side facing slightly rearward.
The other aspect that's better with the stock stuff than any other setup currently on the market for Broncos, is that it's a true cold-air intake system. All the aftermarket filters are under the hood only and so take in only hot air instead of the cooler, denser outside air.
This is not a deal-breaker of course, as many older engines (including '66 to '72 Broncos!) were run this way. But the stock one is still "better" for having the cold-air snorkel.
If the new filter housing does not have the fittings, similar ones are available, or you can make something of your own to connect the two tubes.
The vacuum lines that open and close the hot-air valve on the snorkel can be removed and plugged at their source. I think those are the only ones on a '73. The later model Broncos had more than just the one vacuum circuit on their housings, but in '73 I'm pretty sure it was just the hot-air valve.
Good luck.
Paul
