Can You E-Publish In Word Perfect doc.?

Both at Smashwords and the Kindle set-up area at Amazon, they recommend your novel be in Word.doc, and at Smashwords, I read something about using the "Nuclear Method" to clean up potential problems. Can you stick with WordPerfect and still manage to have a nice-looking e-book? Or, is it necessary to switch to Word, or apply the Nuclear Method?
I was hoping getting my novel ready for e-book publication would be not fraught with as many stumbling blocks as I've been reading about in the guides.

Annoying Convert File Box: Can It Be Bypassed?

I changed my WordPerfect.doc file to a Word one, and made several needed changes like get the line spacing to 1.5 for uploading the novel to Smashwords. But, then I read further that there shouldn't be chapter breaks of more than 4 spaces, and I have some of those.
I went back to my file (a copy) to get rid of this empty space, but got an annoying rectangular box that asked if I wanted to convert my file to Word. The only choices given wre Okay, Cancel, or Help. I want to make the other changes, and whatever further ones might need to be made, without converting the file into anything different than Word.doc.
1.) Is there a way to bypass these annoying boxes? I am using Corel WordPerfect.
2.) If I choose Okay, will the file be converted back to WordPerfect? This is what I'm afraid will happen to it. Though, I suppose if that is what happens, I can make the necessary changes left, and try to rename it as a Word.doc file once again.

Is there a way to bypass the popup box so I can continue making necessary changes? Would it be better to just click Okay, and if the file gets reformatted, then fix whatever else needs to be fixed, and rename it as a Word.doc file again?