OK, so this is a easy question.

What can be removed and still have the run as per normal.

If I can get this ED (hopeing noon else bids), I'll be wanting to strip:
All dash, climate control, power windows, cruise control, speedo cluster, headlights, hazards, inciators, demisters, radio, everything. Plan would be to take the dash out and just mount the BEM on the inside of the firewall. I take it that so long as I keep the ignition barrel and the BEM connected to the ECU it would still start and run no worries? Just worried about things like the speedo cluster especially whether or not it runs without it plugged in. Project would be around building a dedicated strip/track car so most things would be stripped out and I was hoping to run the ED ecu and electronics until such time as an au conversion which would then get the au electronics. Any tips or opinions?
So yeah will it still be OK with nearly everything unplugged and the interior loom chopped up?
Oh and also the speedo cluster would be replaced with autometre gear Im wondering if thats just a matter of finding the right wire on the cluster plug and an earth and presto?
Oh and also if anyone is keen what are people running in regards to exhausts? I was thinking just running about 10cm past the headers bent down and aimed at the ground but thought that e series usually benefit a bit from back pressure meaning side pipes would be the best way?

if ya just want a dedicated track car get a presmartlock EA / EB 3.9 or a EB 4L... no need to have bcm etc. cause all you want is to start the car and drive with no accesssories

Yeah, but try and find me a pre smartlock that is:
<$300
In good nick
Red
Low km's
and less than 1km from my parents house where it will be stored.
Its pure arsse that I dound this one Im not gonna let it go just because of one stupid little thing surely someone has found a way around it if its going to cause problems. Would getting a smartlock bypass mean you are able to bypasss the BEM al together? because that would be handy in the future AU conversion.

Does anyone know for sure?

Get a J3 of TI performance, they can disable the smartlock and tune it, that way you can remove the BEM and most of the loom. Well, you still need the O2 and power steering sensor wiring.

You might be able to remove the ignition barrel aswell and replace it with a switch and push button.

why would you bother stripping a loom of bits you don't need (which will not be fun), only to pull it out and have to do it again with an AU loom??

exhaust wise, run a full exhaust with a straight through muffler.
most tracks these days have noise limits, plus 4Ls with no exhaust sound unbelievably s**t.