As ably explained by @James in his answer, it is far better to describe someone as they are rather than for something that they are not.
Most of the sentences you list just would not be heard. But the expression "not well educated" may well be used from time to time, as are other similar idioms.
It can soften the impact of a statement if you say [x] is "not very" [y]. For example, in British English we tend to use the idiom "not very well" to describe someone who is unwell, but not seriously ill. When someone is very ill we sometimes say "not at all well", which again softens the statement somewhat.
Saying someone is "not very well educated" is not as strong as saying they are "poorly educated". The former suggests something was lacking in their education, the latter suggests something was perhaps wrong with it, and "uneducated" implies no education at all.
Other examples of being intentionally indirect by saying "not" include:
It happened not five miles from this place.
Meaning it happened less than 5 miles away.
Not to put too fine a point on it
Meaning "to be blunt".