1. A metaphysical statement, an a priori synthetic, is going to only ever be "true for you". You, and only you (the rhetorical you).
2. Science generally rests on induction. Its not going to be as 100% true as mathematics. However, this does not put science on the level of theists (read: metaphysical belief) because much of science would be a posteriori synthetic. This would mean its an induction after experience. This means its an experience that everyone could have and theoretically test. Thus a posteriori synthetic wont necessarily be restricted to only being "true for you", like an a priori synthetic would be (metaphysical statements).
3. So yes, science would be on a metaphysical level when ever it makes inductions not based on experience (ie lacks experience, ie lacks evidence). Some religious people complain that when scientists are so sure of themselves, they are basically acting on metaphysical belief. This is not true most of time. When a scientist is so sure of his beliefs, as to attribute deductive certainty to his inductions, he is not being metaphysical, he is merely being illogical.
Again, I believe that people have the right to believe what ever they need to believe, I just think that scientism should not blindly be applied to all of science.