Can we use and alter the SuiteCRM code for commercial use?

Hello,
We are interested in building an application using SuiteCRM. As this is open source,

  1. Can we download and edit/modify the code to suit our requirements?
  2. Can we use it for commercial purpose?
  3. Do we need to have any agreement with SuiteCRM for such activity?
  4. Do we need to pay any charges/ licence to use SuiteCRM open-source Code and features?

Copied from the suitecrm.com:

“SuiteCRM is fully open source meaning there are no license fees or vendor lock-in. This gives you the freedom to create a perfect fit CRM which can be utilised by the entire organisation.”

Also, SuiteCRM is distribuited under the AGPLv3 license:

https://www.gnu.org/licenses/agpl-3.0.en.html