Re the bag question, I always used to cram them in a sales bag, but now I don't bother - why take a bag if you don't need it? I just put my hand of bananas straight into the trolley. I like them yellow-green so they are still firm but (like susie's dad) my mum used to love them really soft. I buy a hand a week so I can eat one every day - they were on offer last week so I put one hand in the fridge. The skin goes black and looks really nasty, but the flesh inside stays firm.
It's pears I have the problem with - Eddie Izzard said once something like "you put them in the fruit bowl and they are stiff as bricks. One morning you look at them and they've gone to mush" - very true, I can never catch them at just the right moment. (and if I may add, lowering the tone as I sometimes do - a pear is a superb laxative. Not going? - have a ripe pear, and give it an hour....)