I use a Ipad Pro with lumafusion it does not get any lighter than that and lumafusion is the best 4K video editor going of course it works with just about any resolution and at 20 bucks for the app it can’t be beat.
In Japan the max height is 120M also you check the nfz map on DJI's web site as all of Tokyo is a nfz you will have to go out away from the city to fly and watch for signs that say no drones as the fine is a steep 5k.
Also you will need to keep batteries in carry on and have the MSDS for the...
As far as I know that’s not supported while the electrical interface is USB I believe the protocol is proprietary to DJI equipment, and it would require DJI to supply drivers for the equipment you want, don’t see that happening
Crystalsky is usable on all DJI drones, the HDMI on it is an output only for a second display feed.
And it gets it video from the USB connection on the Mavic/Spark/Phantom controller