IMHO Mike, s/r, pot, rot are all useful indicators & one should set targets/goals etc, but at the end of each day/week/month if your bank is on the slide then all those wonderful stats that looked so good on paper suddenly count for naught

Speaking solely for myself, bank protection is of paramount importance so whatever staking plan you employ, err on the side of caution & go conservative. You may feel short term this is costing you time & money, but long term its very likely that such an approach will be saving you plenty of both.