Catalytic Converter

Hey! My first topic here.

I've been using this forum for a while and it's been of great use!

It helped with bits and pieces but more recently helped me replace my lower front suspension arm myself and saved me in excess of $200 maybe even $300 (NZD)

Anyway I have reason to believe my catalytic converter is gone!

Why I think it's gone? (Correct me if I'm wrong but all these are pointed out around the internet as how to tell if a catalytic converter is bad.)

A-It's rattling from the inside

B-The car idles rough

C-It wont accelerate over 2000 ish revs

D-It's making a hissing noise

E-When I do manage to accelerate it feels like I'm driving through... a wall of hard air? Not sure how else to explain it.

My question really is in New Zealand it's legal to remove the catalytic converter but is it mechanically a good idea?

I'm a student and don't really have the money to just go out a grab a new one right now.

I would either put a straight pipe through or hollow the catalytic converter or hollow the catalytic converter and weld a straight pipe through it in case of future law changes.

I've also seen that removing it can play with the rear o2 sensor? Is that true?