I guess it depends on the subject.
for story based imagination (movie/book) I'd say it's very poor (1/10 or 2/10), though I have a very good imagination/deduction to guess how a story will turn or end. Authors are always using the same tricks and way to film or depict a situation, things are so obvious.
For everyday life, I might have too much imagination, like "what if that person think this or that, and he/she will react or do that because based on what I said..." etc.
having too much imagination here is probably bad, stressful and near paranoia...
always anticipating other's behavior or what they might think based on what you do is tiring.
9 or 10/10
For different things, like Scifi : do alien exist? if they do, which form they could have if not physical? if physical, why would they be our size, or even human shaped? etc.
if there's something as a soul, and another thing as reincarnation after death, why would it be stuck to earth ? if you die outside of earth (ISS, moon, mars) would you reincarnate on earth or the place you died? if not limited to one planet, were we aliens in a previous life? will we reincarnate on another planet next time?
8/10!