Some questions for start creating WP theme

Dear creators of the Themeforest,
let me introduce myself.
My name is Sergei. Together with my colleague Sergei we have a studio and we are planning to start working on creation of the premium templates wordpress for the future sale on your site.

We have several questions regarding this:

  1. could we work out the template on the basis of framework Alethemes Framework (https://github.com/CRIK0VA/alethemes)?

Does it correspond your requirements for the frameworks?

  1. Are we allowed to use the collection HTML,CSS, JavaScript/jQuery working on the elements (an example of such collection could be the site https://nisnom.com)?

The authors of the elements on this site in the license for their products write that:

"Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge,publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software."

We would like to customize several elements for ourselves and use them in the template.Is it possible?

  1. could we use the fotos made by our photographer? (The rights are his own ones and he gives his permission for using his fotos in the process of the premium theme creation)

If you approve this, what should be done to explain their use?

You can use whatever framework you want if it follows coding requirements:

You can also use whatever assets you want if you have a right license for them:

But it is YOUR job to make sure those assets are properly licensed. Just contact the original author and ask him if it is ok to use those assets in a theme sold on a stock marketplace. Envato won’t be doing that for you.

You can use photos by your own photographer if he is ok with it of course.

If you approve this, what should be done to explain their use

I don’t know what you mean by that.