With a little practice the blimps can be flown successfully. If you have had experience flying RC planes, you will not have a problem flying a blimp. By using small objects such as paper clips, coins, fishing weights, etc. Most blimps are steered with the use of a rudder and propellers which pitch up and down. Yes, most blimps can go in reverse.
Most RC systems are operational for up to one mile.
This is more than sufficient for any indoor blimp. Scotch tape will seal most holes. If the hole is too large, you might need to get a new bag. Yes, most blimps over 6' in length can carry small, light weight video cameras. Even outdoor tethered blimps can carry cameras for outdoor photography.