Important questions to ask china companies?

Hey there!

I've been reading up on china dresses, and am intrigued by this option. I think a China dress will be the only way I can afford to have the dress I want--unless I make it myself. I'm a bit nervous about ordering from China though, because I've read some poor reviews. It seems if things go well they go VERY well, and if they go badly they're horrid.

So, in an effort to make things go as smoothly as possible, what are some things I need to be sure to mention ahead of time? Here are the questions I have so far:

What fabric is this dress made of?
Can you substitute a corset back for the zipper? (I have pictures of this)
Can you raise the neckline? (I will provide pictures of this also, will depend on the dress I choose)
Is there a deep enough seam for alterations if necessary?
Will you mark the dress as a "gift" to help it get through customs? (I've heard this helps?)

That's everything I've thought of so far--what other things do I need to look out for?

Thanks!

which stores are the china companies? I've been talking to one and realized it didn't have any address listed. Then they said it was 95% like the dress they advertized and then they did say you could send it back. No samples of fabric are allocated. It would say they were online to chat but no one ever came in the chat box.