I am looking for printed wallpaper in chinoserie style, which looks like a mural.

Here are some companies you coul

Where can I find chinoiserie wallpapers that look like murals, which are not hand-painted?

Please look at the following designs: Papillon from Harlequin, Hummingbirds from Cole & Son - available from Fabricsandpapers.com, and the stunning range of papers from Fromental.

Where can I get comic strip wallpaper, featuring Superman or similar superheroes?

You could try Surface View, who have a selection of wall murals featuring Spider-Man,  The Hulk, Captain America and other superheroes in association with their agreement with Marvel Comics.

How can I find someone to cover some of the walls in my Victorian house with fabric?

The process you refer to is called fabric walling. The traditional method is to batten out the walls and stretch fabric over the battens, creating a cushioned effect. It is a popular technique in France. We have a section in our Curtains, Blinds & Soft Furnishings category dedicated to Fabric Walling specialists. One company with specialist expertise is Ketcher & Moore; another is Mille Couleurs. An alternative to this method is wallpapering with paper-backed fabric.

Where can I buy wallpaper featuring New York scenes?

Surface View creates murals, prints on canvas and blinds from over 1000 unique and unexpected images, including some New York scenes from Getty Images. They can print them to your exact specifications, and on their website you can see how a chosen product would look in different roomsets. 

If it's actually wallpaper you're after, visit Wallpaperdirect and then enter New York in the box that says 'Search for Wallpapers' and a selection of New York scenic papers will appear.