Bob Hoover was amazing. He was also a genuinely nice guy. I flew with him in the Shrike, N500RA, back when it was still wearing the orange/brown over white paint scheme (yes, I'm old). Did you notice the registration number of the Shrike he flew in that video? N9006N. Kind of an aeronautical palindrome, looks the same right side up as upside down.
As for the question about rolls and loops, all I can say is I wouldn't do either of those to avoid gunfire. Those maneuvers just make you a better target. To avoid gunfire from the ground, pilots do something called jinking; that is to change direction quickly and erratically. Steep banks, and usually descending as low as possible to put something between you and the gun (hills, trees, buildings). Same goes for air to air combat, without the decent though. In that situation, you're doing two things; trying to avoid getting hit, and trying to gain the advantage by getting behind your adversary. In the first scenario, the C-5 would do well. Believe it or not, the FRED is quite maneuverable for a flying building, especially the C-5M we're flying now. Unbelievable power. In the second scenario (air to air), well, FRED is toast. You're getting shot down no matter what you do.
I've actually done some aviation movie work and a fair amount of consulting for film shoots using aircraft (movies, TV shows, commercials...etc.) So, ask away!