Get a UZB Stick for troubleshooting etc! Either the UZB-7, Zooz stick or Z-Stick+. The Z-Stick+ might be good as it has a built in battery but it's more expensive. Since you have a lot of devices the Z-Stick+ might be even more useful.
As previously mentioned pairing certain non-S2 devices will force the device to use S0 security. You probably don't want this for things other than locks or other border devices as S0 is very chatty and can quickly clog things up. To get around this you can pair those devices with a USB Stick above.
For now I would pair any Zooz device with "no security". For other devices it might be okay to just accept the default. I might advise doing a quick search on these forums just in case. Currently most of my devices are paired with no security. NOTE: There is a difference between "S2 unsecured" (second to last checkbox in security popup) and "no security" (no boxes checked).
I would also strongly recommend patience when adding devices etc. During pairing sometimes a device won't finish until the end of the count. Also if there is ever a mesh/device problem It may take the mesh longer to settle than you realize - sometimes a week or more.
The community app - Hub Mesh Details is very useful in showing you relationships between devices - it reformats the Z-Wave details page allowing for filters etc. very handy.
