New guy need advice in backup solutions to move forward

I will start by saying that English isn’t my first language, so please let me know of any errors on my part.
Well, I’m new to Synology. Just got myself an used DS214se to try out and see if this was something for me. But I’ve encountered a couple of setbacks and haven’t been able to find any good answers on Synology’s own forum or anywhere else actually. Just found a lot of people asking the same question.

So for my first question.
-Is the Synology Drive backup seriously that limited, that it can only handle one backup job?
I want to backup separate folders from different drives on my PC to corresponding folders on the Synology but on separate drives. For example I want to backup my Documents folder as a separate folder on one of the disks and then my raw photos in one folder and retouched photos in another folder on the other disk.
As of today I’ve been doing my backups on external USB drives. So the Synology is just my redundant backup. But in Synology Drive I could only create one job and then I had to manually copy the photo folders/files in Drive. But those won’t automatically be updated.

Then for my second question.
-Am I doing something wrong in Drive, since copying is so painfully slow?
When copying a folder in Synology Drive I get a transfer speed around 0,5-3 MB/s. But if I use Windows Explorer (SMB) I will get somewhere around 45-55 MB/s.
Is there a difference in the way it copies the files, like error checking of some sort?
Yes I’m using WD Red disks that are SMR and I’ve read that transfer speeds are slow on these. But why the enormous difference between Drive and SMB? For my backups, speed isn’t really essential, just curious of the vast difference in speed.

So for my final questions.
-How do I get backup jobs for multiple folders and drives on my PC to multiple drives on the NAS that automatically updates whenever a file is updated?
Would it be better to get a second NAS and if so would it then be possible to create two separate jobs that backed up Documents to one NAS and Photos to the other NAS?
Or should I look for another backup solution than Synology?