Ive never used sealer on crank seals or head gaskets. For the base gaskets I use a very fine layer of assembly grease to help the material from sticking as well as it does help create a nice seal. For the NSR metal head gasket, I guess you could do the same (I also apply assembly grease to my o-rings on my RS heads).

For the crank case matting surfaces, you really dont need a lot of sealer (I actually like yamabond), just enough to ocver the faces of the matting surfaces, taking care not to get any in the dowel pin holes, bolt holes, etc..