If I were you I would be doing some testing to see what the interference could be , bring you system to a crowded stadium and fire up the system without the props and see if you have any issues , vary the range etc. I dont think anyone is going to take over your system but a RTH sounds like a possibility . I would use a zoom lens to make it look like you are closer than you are to people . I would avoid flying over people as much as possible if not entirely and use some perspective tricks to get the shots you need.|
Also you should have a channel spectrum analyzer to check the frequencies being used in that environment and also you may wish to have prop guards installed as well just in case , I think I would be more comfortable with flying say a Phantom 4 it is much smaller and has less impact damage if something fell from the sky , also the Mavic has prop guards that prevent any fingers from people trying to grab it .
This is a risky venture as there are so many variables , could you not get the same effect from say a RC blimp that is less apt to fall from the sky ?? I have NEVER had any problems with my system but I have seen it happen.
By the way , the Image transmission is the only thing you have any control over as far as the channles are concerned , I personally would lock on to channel 20 as there is NO WI fi on that channel at all. Likle I said I would do some test runs and invest in a channle spe ctrum analyzer , and then compare to the frequncy chart . Member Daroga had a good chart on that and I will try to find it .
Just my 2 cents .