I’m not ready to publish my website on my business domain yet, that’s why I plan to use a temporary domain or weebly sub-domain during the building and testing phase. I plan to publish the website on my business domain when I’m happy with everything.
My question is, can I buy theme with 1-Site license and use it to build on a temporary domain or weebly sub-domain and later publish it with another (my business) domain?
Yes, you can. The restrictions and issues that happens with the licenses is about having multiple active websites in violation of license type. If you have two active (published) websites using 1-site license, that’s a violation and there’s going to be some issues with the theme.
But in the case as described above, it’s okay to try own different domains as long as only one website uses the theme.