That is a great question. There is also a discussion about Bunkai under "View All Discussions" under Shuri-Ryu. But let me address your question.
You are correct, that all levels - even Omote - are interpretations. The precise interpretation is subject to your knowledge level which should include all of the Moving Forces. You usually can't see something unless you can relate it to something else. For example, the opening mudra in Naihanchi Sho is a perfect example of a Kote-gaeshi (wrist takedown), but unless you have knowledge of the technique it will "hide" from you. Once you learn the technique, then you can easily relate it to other kata where you never saw it before.
The five levels of Bunkai are: Omote, Ura, Okuden, Henka, or Sutemi
The Omote bunkai is pretty much standardized within our system to promote understanding of the basics. Not so with other styles - some of them don't even teach bunkai with the form. Hope this helps - - -
These beginning levels of Bunkai are important to gaining an understanding of the forms techiques and the fact that there are more than one interpretation of each technique in a form. after that lesson is learned the interpretation of technique is ad vast as your mind can take you as long as you understand the mechanics of it.