Question Doubts on RAID enclosure setup

[CrisR82]

With the upcoming Black Friday/Cyber Monday, I finally decided to pull the trigger on a big data consolidation I needed to do for a long time and got myself a RAID enclosure, with an upcoming purchase of a couple of HDDs for it, so I thought now is the best time to ask a few questions to make sure I'm doing this correctly.

The enclosure I got: QNAP-TR002 (https://www.qnap.com/en/product/tr-002)
The HDDs I will be buying soon: WD UltraStar HC580 24TB (https://www.westerndigital.com/prod...ter-drives/ultrastar-dc-hc580-hdd?sku=0F62796)

What I would like to do is have them in a RAID-1 mode, but I have 3 questions that I'm not sure about:

1. Should I use "hardware RAID" with the dip-switches on the back of the enclosure, or use "software RAID" with the QNAP app for Windows?
2. When using RAID-1 (or any RAID if the type doesn't matter), is it possible to transfer the drives to another RAID enclosure (or directly in a PC) and still have them work without formatting them/loosing the data?
3. If a RAID-1 drive dies, is it possible to keep using the other drive as stand-alone without rebuilding the RAID with a new drive? (for example, I have only a few high-risk things I need to make sure are not lost, can I copy just those few files to my PC and then at a later time get a new drive and rebuild the RAID)

Any other info that I should probably know would also be welcome, I have pretty much no experience with these things.

 

[rgd1101]

raid doesn't replace a good backup

 

[CrisR82]

raid doesn't replace a good backup

The actually critical data is already following the 3-2-1 rule, this is "less critical but I would prefer not to lose it since some of it will be a pain to re-do" type of stuff.