A much, much better solution is to use UPX instead of bothering to compile stuff out.
The total header size is 20k after UPX, and you save only about 1kb by commenting stuff out. Download UPX here:
Use it with the following line in a .NSI file:
!packhdr "temp.dat" "d:\upx\upx -qq --best --compress-icons=1 temp.dat"
Check the NSIS help file, there's a little more documentation there (but not much).