" Do you think it is OK to omit verses"

Yes, as the singer you can omit what you want. Whether that's a good idea or will improve it is subjective, so don't be surprised if anyone in the audience thinks you've b*gg*red it up by leaving some of it out.

I sometimes omit verses on the fly, if I judge that the song isn't going down particularly well, or if I get bored with it myself and want to sing something else (or if I forget the words ;-)). But I would only do that in a 'story' song where leaving verses out wouldn't affect the story in such a way as to make it unintelligible.