To answer that I would say a clearly yes to your first your first question.
The different varieties does not taste similar due to using a high processing temp , they all have different properties which comes forward due to using a high processing temperature.
Amongst the different varieties nicotine content varies a bit , one that sticks out a bit is Dark Air Cured , having somewhat more nicotine content.
As I have experienced , if I would have used a temp like 70 80 or 90 C , the very unique properties would not come alive/wake up and I would not be able to enjoy them like I do.
The tobacco needs this this treatment to taste great and another good thing about using 100 C for a week is that the chance it will mold for you is very slim , since you have probably killed every eventual microbe in that tobacco.
Storage in a fridge for a couple of months makes wonders on a well processed snus , it develops by time and the balance of tobacco , water , salt and potash carbonate will be accomplished at the same time.
After 2 weeks in the fridge I start using the snus and it tastes good , after 2 months it is indescribably great.
The big problem when ppl make snus today is that it has to be made quick/fast when good things take time.
This is a reason to why I make a number of batches of snus when knowing they will develop over time , now I might have 6-8 kilos in the fridge.
Color of it should be blackish.