aescobar: I was abit confussed when I first saw this thread untill I noticed that it was started nearly a year ago. I've been using 2.21 for 6 or 7 months now.
As for deleting buildings you can use an exclude switch, that works fine for me, as for taxiway signs they too can be excluded and then using the SDKs from M$ new ones can be made and placed in the right locations.
Steve