Theme development

Hello!
If i want to customize a theme and resell it via webdesign charge, what licences are legal in that case? This licence jungle is quite deep.
Creating a full theme from scratch is to time expensive for now.
I am able to change the drupal default theme but i would like to change a different one.
Thanks for answers.

My website is www.normanandlila.com

I am having errors sprout that point to my theme and do not know how to fix?

I am trying to create a workable commerce site but things are not working?

Any body face any issue creating custom theme using any Drupal 7 responsive Base theme such as adaptive, Zen or Omega.

Please anybody suggest which responsive theme is easy to implement and simple to create custom theme on the top of base theme.

I want to learn more about themes so decided to use Garland as my starting point. I have followed some instructions I found about copying and creating a new theme, these were:

Copy /themes/bartik to /sites/all/themes/YOUR_THEME
Rename bartik.info to YOUR_THEME.info
Edit YOUR_THEME.info, Make Changes, name = YOUR_THEME, description = YOUR_DESCRIPTION
Edit template.php replace all instances of 'bartik' with 'YOUR_THEME'
Goto /admin/appearance
Find YOUR_THEME Enable and set default.

Hello,
I've two different user profile types (lets say: 'seller' and 'customer') and they should look differently conpared to eachother as well as to other content types. The issue is that the profile title (<h1 class="title" id="page-title">My Company Ltd.</h1> should be changed, therefore I think I need a new page.tpl.php for each profile type. After an hour of searching I was unable to find out how I name this page template.
Any advice would be appreciated.

I have a link that is generated on all content types.

But I would like to show this link ONLY to a certain role that didn't create it.

For example, Admin and Admin Assists create a content type, and link shows up when viewed by other roles.

I would like that it be hidden, ONLY when Admin and Admin Assists CREATE that content type, so other roles can not see or click on it because Admin and Admin Assist created it.

Thanks for your help.