Question Disappear in Preview Form

Question #7 is visible when I am in the build mode but does not appear when I try to preview the form.

Question #8, there appears to be a "unknown" category that must be checked in order to proceed to the next question;  the unknown box actually doesn't appear when I am in the build mode leaving me without a remedy to delete it.

Questions #23a/b, again, I can see them when I am in the build mode but not in the preview mode.

Question #24, I am unable to adjust the spacing of my columns and rows.

Also, many of my questions are not required to answer in the build mode but appear to be required in the preview form mode.

Please advise. Many thanks!

I cloned your form and I tested your concern on my end. I disable all the conditions, and I set un-require all the fields. Please check my test screencast below;

I noticed that your all concerns are working fine except the Question 7. I kindly recommend you Duplicate the field. And delete the old one. I tested and this solved the problem.

Please give it a try and let us know if the issue persists.