Answer 1: I have seen it done both ways, but normal setup for this contractor, always run the bidwell on the outside girder. You are correct, lots of extra work for finsher’s. Rails are transfered to overhang for work-bridge after bidwell passes.
Answer 2: IDOT standard practice is epoxy rebar for all structures above ground.
Answer 3: BS mix, for deck super structure
Answer 4: Yes rebar is tied to studs at certain intervals with No. 9 wire
EDIT: There is width constraints not seen in the photo on the right, existing bridge parapet would not allow bidwell to be setup in overhang for this section.