would this make readers mad?

You have two problems that will earn you a load of one star reviews:

1. If I download a short story on Smashwords or BN or Sony that is 4,000, and then it has 20,000 words of a novel excerpt in it, many people will feel like you artificially inflated the size of the book. It won't matter if you put the word count in your description. Particularly with FREE BOOKS. People don't read the descriptions of free things as carefully as they should. They are going to see FREE and see the file size and think they are getting something substantial. And when they start reading and realize that the story ends at location 48 or 300 locations, they will feel ripped off.

2. Let's say you go to your local supermarket and someone offers you a free sample of a new type of chocolate cookie. The cookie is AMAZING! When you ask about availability, the person tells you, "Oh, um, we don't sell this cookie in THIS STORE. You have to go across town and buy it somewhere else." How ticked off are you going to be?

There is also this little thing about professional courtesy. Don't use other retailers as a showroom for Amazon. Because if I am Sony or Apple or BN or another vendor, eventually I just stop working with indies who pull stunts like this. You are essentially using someone else's store to try to drive traffic to Amazon. How would you feel if you paid for a booth at a book fair or convention, and then someone stood in front of your booth handing out free samples that directed people to another author? You would probably think that was a pretty obnoxious, crappy thing to do.

One time I bought a light fixture from a national chain of hardware stores. The fixture hung by these nice, satin-nickel chains. Reading through the instructions at home, I found that chain pliers were recommended for stretching and then closing the chains on the fixture's attachments.

This was a little annoying, since that wasn't printed in the box's "tools needed" disclaimer, but I didn't think it would be the end of the world. The next time I went into the store, I asked them where they sold the chain pliers.

They didn't.

Flabbergasted, I even checked the website from within the store, alongside one of their people. It wasn't available on their website, either.

So here's a national chain selling a nationally-known brand of fixtures, and they don't stock one of the key implements required to install it. Here's the key point: I had to go to a small competitor's website to find what I needed, which I should have never had to do.

I was so upset I went over the store manager's head and straight to corporate about it.

The moral of the story here is: don't tease me with pretty lights and then tell me you don't sell a tool necessary to install them.

Don't include ANY of the novel as a sample. Just don't. Sell what you're going to sell, and bold short story on the product page. Make your blurb small and punchy, which will also help them see "short story". In the "About the Author" page in the back of your book, invite the readers to check out your other works (which you should make available on every platform you can) -- preferably with a link to the product listings pages on your own website, where you have links to each book's products pages on the various websites. And throw the UK readers some help and give them product links, too (or, if you're really feeling ambitious, even more location-specific sites).

Just curious: why wouldn't the novel be available on other platforms yet, since the short story is the only item that went perma-free?