Having lived in Stockholm on and off for ten years my main advice to visitors is avoid November. This is when there seems to be the greatest chance of it being dark, wet and cold without any of the autumn benefits of sun and the crisp winter days with snow and frozen lakes. In mid-October there is still a chance of yellow and red leaves on the trees and sunshine. I remember one October where we had some impressive snowfall over a 24 hour period but it melted quickly. Tourism wise some things are a bit limited at that time of year e.g. boats to the archipelago.

I can't add much to the food suggestions. Pizza is usually cheap although the quality varies as some restaurants are aimed at those wanting to drink 'cheap' strong beer. Supermarkets sell microwave meals if you have access to one where you are staying.