Did any scientists support J.J Thompson's Plum Pudding model before it was disproven by Rutherford?

Answer 1

It was generally held to be a useful model. Rutherford had it in mind when he did his experiments.

Answer 2

Yes, that was the generally accepted model at the time--I don't think there were any other significant theories about the composition of an atom being circulated. It's still cited in textbooks, after all, even though we now know it's false.