This really should be on the Building Tips forum, not here.
But anyway, rotate your sculpt map 90 degrees in any image editing program, and it should solve the problem with the hole and the line down the middle.
To avoid the problem in the future, make sure Correct Orientation is enabled in the sculpty exporter dialog. If you can't see that, or any other checkbox, chances are it's hidden behind a scrollbar. This is due to a typo in the MEL script. Search the script for the word "scrollable". If there's a 1 next to it, change it to a 0, and rerun the script. The scrollbar will go away, and all checkboxes will be visible.
Also, make sure you're using the correct stitching type in-world. What was the topology of your source model? Spheres are stitched along two edges and collapsed to poles at the other two. Cylinders are stitched like spheres, but not collapsed to poles. Toruses are stitched along all four edges. Planes are not stitched at all. Whatever you used for your source model, you have to use the same for your scultpy in-world. You'll find a dropdown box for stitching type, under the sculpt map field, in the editor window.
As for why the sculpty doesn't look like your source model, there could be any number of reasons. I'd need to know more about what you were trying to make, and how you did it ti say for sure, but my guess is you probably made the source model too complicated. It's best not to use more than 16x16 sections & spans in any single NURBS object. Remember, once in-world, the sculpty will only have 32x32 vertices. More complicated shapes should be made from more than one sculpty.
If you need further help, head over to the Building Tips forum, and ask away. There are lots of good folks over there who will be happy to offer advice and tips. You won't get much response to this sort of thing in Resident Answers. That's just not what this forum is for.
Oh, and by the way, just so you know, there's no such thing as "a nurb". NURBS is an acronym, which stands for Non-Uniform Rational B-Splines. To remove the S is to remove the most important word, the subject of the phrase, spline. All the other words are adjectives, there to describe the particular type of spline you're talking about. Without the S, the whole thing doesn't make any sense.
The logic basically goes like this:
"Hey, what kind of spline is that?"
"It's a B-spline."
"Oh, a B-spline, great. What kind of B-spline is it, rational or non-rational?"
"It's the rational kind."
"OK, it's a rational B-spline. Got it. Just one more quesiton, then. What kind of rational B-spline is it? Is it uniform or non-uniform?
"It's non-uniform."
"Alright, so it's a non-uniform rational B-spline. Thanks for clearing that up."
The proper way to phrase what you were trying to say would have been "an NURBS surface" or "a NURBS model" or "a NURBS primitive", not "a nurb".