Preflop:

We're faced with a min-raise from an unknown 1-tabler at 50nl, presumably a fishy player.

Small sample on other villains, so far they seem on the regular side (I played little 50nl zoom before).
For the discussion let's assume they are all competent regulars.

I'm often unsure whether in such occasions to employ a "3bet or fold" strategy or a mixed "3bet some, flat some" strategy.
Intuitively, it seems to me that the advantages of a pure "3bet or fold" strategy outweigh the disadvantages it brings about.
(getting heads up with the weaker player, less exploitable to squeezes when flatting)

Yet I could be convinced otherwise. Thoughts on this?

Constructing the "3bet or fold" range:
IF I were to employ this pure strategy, how should my range look like?
Since I have all my strong hands available, I feel like I should widen my 3betting range somewhat, up to where I like to 3bet approximately:
66+, A5s, A8s+, AQo+, KTs+, QTs+, JTs, 98s (10,4%)

This seems ok? Too wide? Too tight?