If you keep chickens for more than a short while the rodents and wild birds are going to find the feed. Along with the stolen feed both vermin bring in disease and mites and a host of other pests/vermin. Plus the rodents and wild birds are going to attract their natural predators like snakes and raptors.
A good treadle feeder will keep the feed dry unless you have a storm capable of blasting the feeder with sideways wind and water. Normal gusts and wind blown rain shouldn't cause a feeder to leak. Bonus points if you can put a shed roof over it for when it is raining and a bird uses the feeder but that is not necessary usually.
Doesn't matter if you take the feeder in at night, the rats will eat when the feed is available. The predators will notice the rodents and wild birds and will view your yard as prime hunting territory. Rodents even leave a trail of urine that some raptors can see that humans cannot see.
ALL feeders carry some minor risks if they have moving parts and a swinging door. Follow the directions, use them for adult birds only, not chicks or under one pound pullets, block the sides with something like a milk jug of water or a concrete block to force them to come in from the front. Inward swinging doors are much safer, a soft close feature helps make the feeder more safe, but if you are going to keep the rats and wild birds out you are going to need a spring loaded door and a heavy counterweight. That said, even a poor treadle feeder might keep the wild birds and rats from finding the feed in the first place but most feeders have no spring loaded doors or counterweights and the doors are easily pushed open by rats and wild birds if they know where the feed is located. Above all, never block a feeder open. Train them from day one to step on the treadle. And once they are hungry birds are clever and fearless.
Your choice is to pay now or pay later. You either buy a good rat proof treadle feeder up front or you pay for the feeder by increased feed purchases. Watch your feed consumption, anything over a quarter pound of feed per day per adult bird means you are feeding more than chickens. And do your research. Read the reviews, anything over five or ten percent critical reviews is a problem. There will be people that cannot be satisfied or can't assemble anything more difficult than a hot dog but anything over 10% critical reviews needs close scrutiny because most people write reviews within a few weeks of purchasing the product and usually there hasn't been a problem yet. The negative reviews are the clutzes and the real problems showing up after a few months.