Nah. Might as well be becoming more acidic. Or, even more likely: not change at all in terms of pH.
Foaming and pH don't have much to do with each other.
To the extent that running film through a developer will influence the latter's pH, it will be a pH decrease, not an increase.
Not necessary. Just ensure the reels are entirely submerged and don't slide on the center column.
Also, people seem to forget that air is lighter than water by a huge margin. Foam floats to the top. It's only a problem if the fluid volume is too low to begin with, or the reels end up sitting partly above the fluid level. It's possible that some tiny bubbles stick to development reels and thereby form a narrow band of low density along the edge of the film (where it's typically not noticeable in the first place). But large areas of foam like this can never be the result of sufficient developer volume combined with foam. It's just physically impossible. If you don't believe me, go sit in a bathtub with lots of nice and fluffy foam, and see if you can get the foam to float under the surface of the water. Take some scuba gear into the tub, if you please. And a rubber duckie.