Some help needed after RS 3.8.14 mounting issue

I have a RS stable installation with 2 3T drives in RAID 1 and the OS running from a flash USB drive.
Most likely caused by the known issue of 3.8.14 sometimes not mounting all the drives, the system is somewhat messed up now.

At some point the Samba shares would turn ReadOnly, and not having the time to look into it, i rebooted the NAS a few times. I did not get any clues in the GUI, but later in the terminal i could see the drives getting mounted readonly.

“btrfs filesystem show” indicated that a drive was missing.

unpluggin one and later the other to see with one is the culprid, both drives seemed to be oke.
Smartctl -t and -a showing no errors. With single drives Btrfs recognized them as part of “Main”, complaining about missing a drive

after plugging in both drives “Btrfs filesystem show” now again sees both drives.

[root@rockstor ~]# btrfs filesystem show
Label: ‘rockstor_rockstor’ uuid: 6e5c1ddb-036f-4b83-a07d-2d7806d845bb
Total devices 1 FS bytes used 6.64GiB
devid 1 size 12.51GiB used 9.35GiB path /dev/sda3

Label: ‘Main’ uuid: 7ffe6a5f-bbf1-41fc-8596-9fc36573fcd5
Total devices 2 FS bytes used 1.78TiB
devid 1 size 2.73TiB used 1.80TiB path /dev/sdb
devid 2 size 2.73TiB used 1.80TiB path /dev/sdc

And as far as i can tell, BTRFS is still using both drives in a raid1 configuration:

[root@rockstor ~]# btrfs filesystem df -h /mnt2/Main
Data, RAID1: total=1.80TiB, used=1.78TiB
System, RAID1: total=32.00MiB, used=304.00KiB
Metadata, RAID1: total=5.00GiB, used=3.44GiB
Metadata, single: total=1.00GiB, used=9.59MiB
GlobalReserve, single: total=512.00MiB, used=0.00B

But the GUI now indicates the pool as single with no redundancy

And while the samba shares are still working:

All settings seem to be lost in my Samba configuration.

1: do i still have redundancy for both data and metadata?
2: how do i get Rockstor to recognise the Main pool in a correct way?
3: what is the easiest way to get back my Samba settings? (home and root have daily snapshots going way back)

4: what is the best way to see that your system is healthy? Thusfar the GUI and my mail alerts did not alert me. Even when the drives were mounted readonly

In all, there seems to be a disconnection between what is really happening at the OS level and the GUI level.

thanx for your ideas.