"I for one welcome our fairy overlords if, as and when they choose to reveal themselves."

Kent Brockman

Yes.

No. If you are naturally sceptic and rational, then there is no problem applying both to everything. But you may still use judgment, to apply imagined and certainly not confident probabilities, for working purposes, especially when 'hard' evidence is not available.

There are many different ways of thinking about things and knowing. The important thing is not to make the mistake of, awarding equal value to all of them. For example I do not 'know' if dragons, the Marsupial Wolf, or the extinct Large Blue Butterfly once found in the southern counties of my own country exist. But if you invited me to go on an expedition and look for them, I would be quite reasonable to conclude, using judgment, that. Going looking for dragons, is a total waste of time, since there have never been any credible claims to have seen them. The Thylacine is large hard to miss, and there have been no sightings for a long time, apart from some highly dubious ones, therefore almost certainly a waste of time. The butterfly however is small and easy to miss, and was certainly seen within the last few decades, by credible sources, so that is possible.

Every thing you think you know could be false, but for practical reasons we have to stop short of total disbelief sometime.
It is best therefore to award values to different forms of knowing, something like, but not certainly.

1. Evidence of your own senses.
2. Evidence of credible sources own senses, especially those who use the experimental method and peer review as checks.
3. Things reasoned by logic from the evidence of the first two.
4. Good philosophy. Which does not clash with the first three ( Which is really three made by credible others. )
5. Value judgments applied to the evidence gain from the first first four.
6. Popular opinion by those known to value the first four.
7. General popular opinion (Includes religion).
8. Unpopular opinion (Includes cults).

Personally after nearly sixty years I have never found a need to venture beyond six.

Yes, a big difference.

No.

Leave the pretty pagan girls alone watering their gardens with belief Tinkerbell and comrades sprout like worms from soil to be captured and hooked for fishing down by the pond.... Agnosticism is a fools playground aside Atheists fighting criminal theocrats and creationists attacking school classes teachers and real science books..... methinks ye stirring up tempests in yo teapot

Fairy exist.

Fairyflies are very tiny insects, like most chalcid wasps, mostly ranging from 0.5 to 1.0 mm (0.020 to 0.039 in) long. They include the world's smallest known insect, with a body length of only 0.139 mm (0.0055 in), and the smallest known flying insect, only 0.15 mm (0.0059 in) long. Wikipedia

Whut? o_0