Adding custom fields to the poll module

I am creating a polling site in D7 which will allow users to create their own polls. However I would like to add some fields to the poll module such as checkboxes (to allow multiple answers, allow users to add their own choices), a reference field for categories, an image field and a couple of other fields. I've been fumbling through Drupal for about 3 months now and I'm not sure how to approach this problem. Is there an easy way to do this that will create the necessary database fields or do I need to code the schema as well? The approach I'm currently taking is to copy the poll module to my sites/all/modules directory do a search and replace of 'poll' to a new name. I added the fields using the form api in the modified poll.module file, although I have yet to figure how to add the term reference field and then save the values in these new fields to the database.

I tried using the webform content type. however there are no Image and Term Reference field types within webform. Is there a way to add more field types to the webform?

I would really appreciate it, if you anyone could point me in the right direction.

Thanks