Widget Registering for One Page WordPress Theme

Hi There,
The theme I have been developing for themeforest submission is a one page WordPress personal portfolio theme. There is no widget in the main page design which is the only showcase page of this one page theme and I didn’t set any widget in that page.

But I register a sidebar in footer for other pages like index.php, page.php, single.php, archive.php, search.php etc.

  1. Q. Is it ok not to set widget in the main page?
  2. Q. Is it allowed to register widget in the thememode(not as a plugin)?

Thanks in advance