"The knowledge and vision to see things clearly" (yathābhūtañāṇadassanaṃ)
1) Yes. When the Buddha spoke about vipassana, he meant it as being the direct insight into reality.

What is being taught as vipassana (depending on how it is taught) is supposed to be the training which will lead us to vipassana.

As far as the Buddha-Dhamma is concerned. Meditation training means: Abandoning, letting go, of craving and clinging. Which will lead us to vipassana "clear seeing".

The whole path of the Buddha-Dhamma can be summarized with this short sentence;

"Nothing whatsoever should be clung to".

Or as Ajahn Buddhadasa would express it: "Nothing whatsoever should be clung to as being I or mine".

The amount of training (sitting meditation) that must be done, will depend on the mental faculties, moral purity, weakening of mental defilements, equanimity, understanding, wisdom etc.

Abandoning or letting go of craving and clinging should be practiced day and night, until complete cessation of craving and clinging.