A few more considerations:
- wood dust can be surprisingly dangerous — potential for spontaneous combustion, even prosaic domestic species have intrinsic dangers: walnut is aleopathic (inhibits plant growth), cherry can be poisonous to some animals
- one should consider the constituents of alloys / metals — some copper alloys contain beryllium, I also wouldn’t machine any lead alloys w/o significant preparations and care and cleanup — if you don’t understand the dangers posed by a material and its specific safety considerations and are able to accommodate them, don’t mill it.
Placing a rubber mat underneath the machine will help reduce noise a bit, as will putting the table it’s on on carpet.