your original questions or concerns from a 'new to rving' prospective bring about one main 'rule' when RVing: there are NO rules.
meaning: yes, run the generator anytime you wish, it doesn't know the difference, or care
yes, run you fridge anytime you wish, anyway you wish, it doesn't know the difference, nor does it care
so, don't 'overthink' RVing - go with what works for you and your situation. They are built for just that very option.
'14 Palazzo 33.3 bunkhouse 34' diesel
KingTailgater2 Dish HD, 100w/5a SOLAR, BlueOx
100,000+mi since '14 - US, Alaska, Canada - Hiawassee, GA! (also, '14 Gulfstream Amerilite and '07 ForestRiver Rockwood) : )