I am a non-smoking, single, straight female interested in sharing cabin costs on some future cruises too. I have also cruised extensively but except for one solo cruise with a group, have always cruised with family. I have cruised with the cruise lines you mention, except MSC, and also like Princess as well.
Although I will be continuing to cruise with my family on occasion, I would like to cruise more but would also like to avoid the single supplement. I am very interested in cruises from Galveston and also would like to take the short coastal cruises that Princess is offering this September from Vancouver. I also prefer outside or balcony rooms.
While I don't drink alcoholic beverages, I don't object to a roomie drinking wine or socially--I just don't want to share with a partier. I prefer traditional first seating dining and also enjoy the ship activities, touring, and beach/snorkeling . But I too am independent and don't expect that we would be constant companions.
If you are interested, please post back and then perhaps we can exchange email addresses and "talk" more to determine compatibility.