Have these extensions been tested? How good are they?
Yes, every widget goes threw a extensive testing phase before being released and all widgets adhear to magento standards and best development practices.
If i have 1 production (live) website and i have another development server do I need to purchase multi-licence?
No the multi-licence is only when you have multiple (live) production websites. You can use the single domain licence on as many development / test machines as needed.
What versions of Magento do your widgets support?
All widgets are compatible with magento 1.4 CE / 1.6 EE / 1.7 EE / 1.8 EE.
How do i get my widget after purchasing?
It is available for download instantly via this website. You can also email directly at magewidgets@gmail.com with any questions.