for that I would not buy a mycloud especially not an EX4 the NAS will be VERY slow perhaps to slow for video editing.
buy a simple raid 1 dual drive external drive where all the data written to the 1st disk is ALSO copied over to the 2nd disk. Use USB3 for fast connectivity to that external disk.
then get an Amazon Glacier online account and some mac/pc/linux whatever you use software to BACKUP that external disk to an amazon glacier cloud account
now you’l have your photos/home videos redundant locally, w/ fast access and backed upto inexpensive cloud tape backup in case anything catasprophic happens locally.