"To be all things to all men"

The idea for this post comes from here: http://freds-ramblings.blogspot.no/2011/04/something-to-think-about.html
"Know how to be all things to all men. A wise Proteus, he who is learned with the learned, and with the pious, pious: it is the great way of winning all to you: for to be like, is to be liked. Observe each man's spirit and adapt yourself: to the serious, or to the jovial, as the case may be, by following the fashion, through a politic change within yourself: a veritable necessity in those who are dependent. But this great rule of life calls for rich talent: being least difficult to that man of the world whose mind is filled with knowledge, and whose spirit is filled with taste." (Baltasar Gracian)

The topic is so interesting, I'd like to share some thoughts.
Well, let's say, I divide people roughly into 5 groups:
1/ Inflexible. Frank and straightforward to the point of being rude and unpleasant. Open. Cannot hide their own dislike, aversion, contempt. Can scarcely be insincere (though once in a while they have to). Sometimes tactless and insensitive, mistaking rudeness for frankness.
Not bothering to please others and win friends, these people can create difficulties for themselves- become unpopular, get into trouble with people, displease employers/ teachers/ colleagues, hamper their own careers and may even create many unnecessary enemies. There might even be something egoistic in their insistence on voicing their thoughts and staying true to themselves regardless of whom they're being with, in their refusal to adjust their own manners to different people.
E.g: Marianne Dashwood, Bazarov, LC, HT, me (especially back then in high school), etc.
2/ Inflexible. Can never be two-faced because they are simple, artless and genuine (and not good judges of character), rather than because they have a strong personality. Such people are more likeable than those in the 1st group, but may encounter problems of a different kind, such as being used.
E.g: Catherine Morland, Harriet Smith, Sj, etc.
3/ More flexible. Sensitive, tactful. Adjust themselves to different people. Talk about things in which the other person is also interested, avoid topics that might lead to unnecessary conflicts. Express opinions in a way that doesn't insult others, choose words and phrasing with care but do have opinions, especially in important matters. Civil and polite without becoming deceitful or insincere (e.g seeing something horrendously ugly, they say tentatively that it's OK/ nice/ all right..., not wonderful/ gorgeous/ amazing). These people do have a clear idea whom they consider friends, whom not, and generally keep a distance from those they don't like, unless they're forced to work with them, i.e don't try to be close to those they don't like.
E.g: Elinor Dashwood, Anne Elliot, J, M, DC, etc.
4/ Flexible. Can adapt to different people. Diplomatic. These people are not exactly deceitful and manipulative, but they try to maintain a relationship with everybody and create no enemy. Generally liked though possibly not to depend on. Stand up for no one and defend nothing. Stay away from trouble, never get involved in other people's problems, even friends'. Have no opinion. Survive.
E.g: Oblonsky, NT, MA, MT, etc.
5/ Chameleons. Hypocritical, manipulative, cunning, calculating, dishonest. Friendly and affectionate towards everybody. Say what others want to hear. Master the art of flattery. Talk around anything, can always justify themselves and change their own meanings. Very popular.
These people are very likely to have influence, to succeed and to move up the career track. Can easily achieve what they want. Can also have lots of acquaintances. But because they are unreliable and, due to their deceitful nature, are not open, I doubt that they can have very good friends. They can be very close friends with those of the same type, with whom they can discuss their schemes and everything, but these friends are also deceitful and therefore untrustworthy.
E.g: Lucy Steele, Isabella Thorpe, Caroline Bingley, Susan Vernon, Mary Crawford, William Elliot, George Wickham, S, V, QH, etc.

(This is very general, so don't give me a fictional character or a real person and ask me which group he or she belongs to). 

Baltasar Gracian's quote, if you look back at it, may refer to type 3, 4 or 5. As type 3 is the best way for which we should strive, there is a grain of truth in the advice, but I cannot completely agree with the quote- Baltasar Gracian's phrasing makes me think more of people in group 5, the obnoxious phonies. I detest hypocrites more than anything.
People in group 4 are, on principle, better, but they are less detectable and may sometimes cause much deeper pain. 
Me? I think like Anne Elliot: "She felt that she could so much more depend upon the sincerity of those who sometimes looked or said a careless or a hasty thing, than of those whose presence of mind never varied, whose tongue never slipped."