Welcome to the forum!
I used to have a 4½ qt KA, I got in '76 for Christmas, and a friend still has it to this day! (I got a 6 qt one, to make larger recipes in!) I found that good for bread recipes from 6-6½ c flour (any more, and I had to hold the dough in the bowl with a spatula), so that should be good for 4½-5 c flour in the recipes. And I'd be able to make 1½ standard cookie recipes, using 1½ sticks butter, and 3 c flour, so you should have no problems with 1 stick butter and 2 c flour. Might be able to do 1½, but when these things get overloaded, the dough tends to climb the hook or paddle. And hopefully the mixer came with the scraper paddle - something that is attached to a paddle, to scrape the bowl, while beating.
Have fun cooking!