Congratulations! Sounds like a great color combination, and I can't recall ever seeing one__and I've seen A LOT OF THEM (between eight years of attending Homecomings at the factory and the continual parade of them through my garage). PLease post up some pictures with the top up/down and showing off that interior.
Every single one of the issues you mention has been covered in this, or "the other forum" so with a little searching, you'll find answers and solutions.
As for getting the other 75 hp back, it is waaayyy more cost effective to bolt on a Vortech supercharger. This modification can be reversed at will, and you would not have rendered the car unsaleable (I for one sure wouldn't buy a car that somebody hacked in a non-original engine__way too many little details to get wrong).
Enjoy, and you should try to maintain a presence on these forums, as you'll get a lot more pleasure out of your ownership experience from the knowledge base here.
1957 Austin-Healey 100/6 Wine Red
1961 McCulloch R1 go-kart Screaming Yellow
1995///M3 Coupe Dakar Yello Eurosport Twinscrew S/C
1999///M Rdstr Cosmos Black Eurosport Twinscrew S/C
2001///M Rdstr Steel Gray
2011 X5 35i Sport Deep Sea Blue/Cinnamon