Cleaning twicr a day of the cabin, Yes just let your cabin steward know you would like both.
Drinks included are water, iced tea, lemonade during lunch on the lido, orange juice during breakfast, as well as you'll find little smoothie drinks during breakfast at International Cafe and the lido, in the MDR you can get milk, juices, hot cocoa, tea, and coffee.
Yes you could take one bottle of wine per person on the ship.
Southampton to London you can either take the Princess Cruises bus transfer, or you could take the train which would be the cheapest route versus like getting a cab.