Couple of Q's about a 79- kinda longish

[jsoutherland16 at attbi.com (Jeff Southerland)]

First let me say thank you to Ron and Al for the video hook up, haven't watched it yet, but I can't wait to see it.

Now on to my questions.  I have a 79 that is soon to be my daily transport and need some advice. The injection was swapped from my 84 GTi, CIS w/Lamba, and I was wondering if the O2 sensor needs a Cat to function properly. 

How much of the EGR system can be removed?

How much of the vacuum system -canister, amplifier, that kinda stuff- can be removed with no negative effects? I saw the tech note from a couple weeks ago, is it pretty much the same for the mk1?

 I want to swap the dizzy for a hall sender unit and I read somewhere the vacuum advance/retard may be better than mechanical. Any thoughts?

And last but not least, has anybody put a GTi rear bumper on a mk1? I have one, and boy is it lighter than the stock one. Just wondering how it looks and fits before I waste time on it. 

Thanks for the time and any thoughts are appreciated.

Jeff