If my gi tract was in tip-top form, 100% perfect, would i still get gas from eating beans (black beans, lentils, and kidney beans specifically)?

Yes: Intestinal gas is caused by bacterial fermentation of undigested food stuffs like the high fiber items you describe.

Yes.: You would still have gas production from the undigestable starches in your diet such as those found in legumes ( beans). Beano is an enzyme ( Alpha galactosidase) that digests many of the undigested starches in your gut and reduces gas production.