For the pool, it probably depends a lot where you live. Our power company recommends ours be on for 4-6 hours per day. I'd check your power company energy conservation page for suggestions as they are likely to know your climate specifications rather than asking the pool guy (ours tries to change it to on 12hours/day every once in a while). There are variable speed pumps that use less energy as well that you can upgrade to, but they are pricey so you need to do the calcs on the energy savings yourself.
For water heater, I've heard the rule of thumb is 120F for most people is fine, but to go higher if you're doing things like washing cloth diapers, etc. If the insulation in and around your tank is fine, you're likely not losing a lot of heat from the hot water just sitting there, so moving to a smaller tank probably wouldn't save much energy since most of the energy is used heating up the water initially when it gets to the tank.