I am not up the snuff on some of the older zwave technology. Looks like FGK-10X is a Fibaro door sensor. You say it is non-plus so is this what I have seen people calling a FLiRS device?
I am not sure how a door sensor would work well if it is not sending out immediate status reports, which is what ZWave Plus is all about AFAIK.
You also have a bunch of sensors paired with S0 security which adds a bunch of overhead. Unfortunately there is no easy way to pair them without security.
Anything that is Zwave Plus, with Security None should be safe to hook back up right away. Check the settings for those and optimize the reporting to be the least frequent you need info from the devices.
Grab this app and set it up, it shows some additional metrics I think might help, like the number of messages. We will be able to see if a particular device is especially chatty. : [BETA] A Z-Wave Mesh Tool [C7 and 2.2.4+ Only]
Your Boiler, Hot Water, and Freezer "Power_Switch" devices look to be struggling, I assume they are plug/outlets. Are they power metering or just on/off?
