As far as changing too often I doubt it. For me even at the most extreme every two days, but it doesnt matter if you can and want to change every day, no problem.

Not many birds here either but I noticed a couple yesterday and as I type I see one out front on the first nature and buzzing around the coral honeysuckle , no fighting since seems to be only one at a time.

My lone feeder is mostly in the shade with some weak sun in the morning and a bit more in the evening. All season I've been cleaning/refilling every three days when the temp is below about 85. Above that, which has only happened a handful of times during this very cool summer, I go to every two days. I suppose if it really gets cool for an extended period I could go to every four days.