NA help need advice on custom exhaust, air pump removal/auxiliar intakes
 

Hi, i got 1987 NA rx7 fc to restore and want to make an exhaust. After all the search i've done i see a lot of different opinions about removing the air pump some say it's okay other don't advise to do it.

For what i know the 5 and 6 auxiliary intakes on my engine open with the cat-back pressure, and the rotary engines get to temperatures very high so supposedly the injection of air in the cat cools down the exhaust.
I'm thinking on buy a header and some mufflers and put a straight line. This would implicate getting a new pulley kit with only water pump and alternator, and as i'm thinking make an exit on the header to use the pressure to open the auxiliary intakes.
I got a remove the air control/check valve and buy a cover plate too.

The big question is will it work? it's bad for the engine or not?
Another thing, do i have to work something on the ECU reprogram or something? I already got an K&N filter to put on but no MAF.

I live in Portugal and it is a pain in the ass to get parts or a mechanic that works on this cars, so i got to do it all by myself. I really need a help from someone more into the subject than me....