Despite the fact that you're utterly doing my head in with this thread, I'm still going to answer this sensibly. Or try, anyway.
First off go and see what a plenum spacer does, and then see what the MAF does in relation to the AFR of the engine (these are easily searchable both here and in Google), and then work out why sucking huge amounts of air post-MAF is a Very Bad Thing Indeed. If that is the case, then I wouldn't be driving that car at all if I could help it, and I certainly wouldn't be going over 3K rpm.
Remap will do nothing if the mechanicals aren't set properly. Out of interest, does your CEL still work, i.e. does it light up pre-ignition on the light check? I ask as you really should be getting a code if you're running lean enough to lose 100bhp... Also, you say the guy who did the dyno did three runs, yes? Then if he knew the car to be so lean that he advised you not to run it over 5K rpm, which he would've found out on the first run, then why the hell did he do two more runs?!
At this point you need to forget any hopes of a remap and start taking stuff apart. There is a guide on here on how to fit a plenum spacer, I would suggest reading it and checking all the bolts are torqued correctly first of all, and listen for any leaks around the plenum if possible.