1. NEVER let anyone get close to that door!
2. Closer to some foot pursuits, but farther from others. No net gain.
3. Simply not so, in any patrol vehicle I ever used. A major reason that I chose to carry on the right hip, even though I am left-handed, was so I could have better access to my duty handgun, while seated in the driver’s seat, inside a patrol vehicle. (One-person cars were the norm.) When I started training and evaluating rookies, I had to ride shotgun 3+ nights a week, and, until we started using Chevrolet Tahoes, access to my right hip was seriously compromised, while in the passenger seat.