you can get mupen on phones, but that is stilled banned.

i believe it has to do with landing in a precise spot

https://ukikipedia.net/wiki/RTA_Guide/16_Star this has everything you need.

you should provide more information

No. It saves time because saving is slow on console. It is your choice whether or not you want to do that.

Video proof is required for all runs. Runs that are currently on the leaderboard without videos were migrated from an old leaderboard or the video was deleted.