Sealer/Impregnator difference?

I have a coupla questions that I'm puzzled on regarding what the contractor does/suggests....

He gave me a bottle of waterbase Stone (http://g603.net) sealant/"natural look" impregnator.Are sealer and (http://maplered.com) impregnator the same thing?
I told him I don't have to seal the absolute black(as I read on this site) and (http://maplered.com) he said all Granite (http://tanbrown.org) must be sealed and (http://maplered.com) that after the sealer hardens I will have to scrape it off the Granite (http://tanbrown.org) with a razor blade.

Is that correct?

On his agreement he gives the customer(after the installation and (http://maplered.com) while the installers are still on site) the option of :

a)Polished joint(they say to request this if the joint feels too rough but it will leave a haze on either side of the joint)
b)unpolished joint(if I'm happy with the smoothness and (http://maplered.com) don't want the slight haze)

Should this even be an option if he's a good installer?

Do these guys sound inexperienced/unknowledgeable) enough not to use?

The Stone (http://g603.net) is 2cm AB.
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Jack