I sterilize my baby's bottles after each use. When my twins were babies, they both had thrush (probably from the bottles not being sterilized) and I do not wanna go through that nightmare again.
Each night I fill the sink with soapy warm water and let the bottles soak a while. Then I clean them with a bottle brush. Then I put them in the dishwasher each night. If you don't have a dishwasher, put them on the stove in boiling water and it's just as affective. I store them on the bottle drying rack. I hardly ever put them away because I know I will use them all the next day.
I wouldn't recommend storing them in a plastic container. If they are the slightest bit damp, mold or mildew can begin to grow.
I think I answered all your questions. Good luck