Yes, 2b is a really appreciated and standard darkness for leads, but the thing is if you go darker the lead will wear out faster as it leaves more graphite on the paper eveytime you use it.
That is the link for the erasers Im talking about!
And yeah Ahaha there is so much to consider, but it’s always a matter of personnal choice at the end of the day. The grip can be a problem for some if they have sensitive skin, if you have « moist hands » it can be a plus to have more agressive grip, etc. And the color in itself really is a personnal esthetic choice, but from experience and owning a few rotring in both black and silver, the black ones looks better I think but scratch a bit more easily.
If you want to know anything else, let me know ! And also, there is much more pencils brand than rotring, and some REALLY great models out there !