I just hooked up my HW 2.3 OS this past weekend (it ran it’s first scheduled program earlier this morning) and haven’t seen any of the problems you are describing thus far. The only oddity I experienced was related to DHCP and the TPLink wireless adapter (OS lost the original sticky IP I set on the DHCP server), but I chalked this up to weirdness with my wireless access point as it hasn’t reoccurred since rebooting my access point (and my OS and TPLink).
My current setup doesn’t let me check if OS is ARPing with multiple macs, so I can’t report on that one.