Your answer was very good. Here are some added info:
1. On the GT1 esprit there where another plendum made out of sheet aluminum. The reason for this is that the stock plendum is a little restrictive, but it also fits nicely. The made plendum is much taller. Also the made plendum does not separate the cylinder sides. You also have to consider that lotus used only 1 large turbo in the beginning. At later stages I don't know if they used a twin setup. Today the GT1 cars are GT2 cars and are for sale.
You can proof that you need both dump valves by just disabling one intake side. With an analyzer you will see that one engine 1/2 would suffer more than the other It will not be balanced!!!. So unless you want to remake your plendum use 2 dump valves.
2. If you remove both cats and if you reinstall all 4 O2 sensors. Your MIL will not turn on. I drove my car 6 month w/o cats and no MIL light with a standard ECU. I have done 2 other cars like mine and they have no MIL light turn on. But maybe I am special or my secondary O2 sensors where off to begin with
. If you have a problem, a couple of resistors could perform some magic for you.
3. To begin with, the Lotus injectors are cheap crap. (bad patterns, plugs easily ETC ETC ETC). You would need them only after reflowing your turbos if you want max performance (The ECU will balance itself to the injectors). After some testing my injector duty cycle where much higher than 80% at 1 bar. Besides maximum boost is .65 bar with the stock ECU. Now you add reflowed turbos, cams, intercooling, exhaust, porting, ECU (modified race), and more fuel is necessary.
4. Transmission cooling is definitely necessary if you are racing the renault. However, the biggest trouble with the transmission is its design. It has very long shafts. If you put a lot of power on the 2nd gear, the shaft would bend and you will wear the gears on the edges, which in terms will strip. I have friends racing Trophys with renault 21 transmissions and they have to rebuild them after every race. I am in the process to install a G50 transmission instead.
Lew installed a transmission cooler onto his car. I will publish the installation on my website this month. Also the cooler is VERY loud.
5. You just make a box for it. Its not on the website yet.
Another couple of things to consider. After you do any major mods to your engine, change your main bearings. They are way to thin to handle much power and will fail quickly. The stock bearing are using a VP1A ("A" denotes a 14 micron lead indium overlay) bearing and the racing lotuses are using a VP2C bearing ("C" denotes a 20 micron lead indium overlay)
Also you may want to relocate your knock sensor.
Regarding body panels: Where did you find them. The only place I knew about is in Belgium and they are not making them anymore.
If you are interested in performance mods join: http://groups.yahoo.com/group/ExoticPerformanceCars
it a very lotus heavy group.
The racing ECU "red" has only slightly modified boost and fuel mapping. We are presently rewriting some of its code.