There have been a few reports of Schlage Connect (BE469/BE469) problems lately. Staff have stated they have plans to address these problems in a future firmware update with a dedicated driver for the lock. That being said, I'm not sure the exact problems this aims to address--adding lock codes seem to be one: Adding user lock code failed on schlage lock
The rest might be a separate issue. Are any of your Z-Wave repeaters beaming devices? (Check their Z-Wave Alliance certification document if you're not sure.) Have you run a repair since adding/moving any?
I also don't think you should need to poll the Schlage, though I doubt once an hour is going to cause any problems. For the slowdowns, is there any reason to assume it's specifically lock-related? Do you have any custom apps or drivers? Do you see lots of errors (or just excessive logging or anything else worrisome) in your live (or past) logs?