First, no experience with anything other than Windows support (laptop, desktop with a 2nd Microsoft account accessing only shared folders, tablet and phone) for One Drive. It works, now better than ever. I understand Microsoft has done a good job allowing access to One Drive from Android and Apple systems.

Basically, what I like is that I control what content goes to the cloud by just putting the content in a One Drive folder, or not putting it there. I like having secure access from all my devices to my files. I like having my raw camera files go to the cloud with a local offline copy. I like being able to show my select photos from my phone as a mobile photo album. I like knowing that the day after I have taken photos with my dslr, I have them stored in an offsite location. With my Microsoft account and Office 365 subscription, I expect to have enough space with the 1tb allotment for a couple years. I can decide what to do then.

However, proper protection includes having my own local backups. That should be the start of any recovery plan. Only stuff that I've done since the last backup should need to be downloaded.

Your needs are different. Those large video files should maybe still be dealt with only by a local backup system (rotating the backup disk to an offsite location). You will likely be willing to rotate backup drives for your video files. All the rest can be done similar to my system. That way, your minor editing changes to a spreadsheet can be on One Drive and be offsite and available to other devices immediately. You probably won't do a backup for them and would lose the changes when a device like your iPad fails. One Drive solves that problem.

As far as security, I'm quite comfortable with the way Microsoft is handling things. Warnings about new devices accessing the account; warnings about mass file changes; ability to recover from that. I think Microsoft had a huge security haircut back in the early 2000's. They understand the risk to their business if they don't protect you better than almost anyone right now.