A:AnswerIt’s the latest generation mini iPad
The online billing depends on which server your using to access the bill pay
Ie PayPal and also if it’s a secure internet
Network
The battery life is superb and a lot better than similar brands as u mentioned
A:AnswerYes you can definitely download photos from an iPad to a windows computer. Simply plug the iPad into a free USB port using the lightning cable you use to charge the iPad. Modern computers will download a driver and iPad will be listed in my computer, from their you can copy and paste the photos. The alternative is to install iTunes which will backup your device automatically. iTunes can be downloaded from Apple.com/iTunes
A:AnswerThe AT&T (or other carrier) models have their own cellular service for internet in addition to WiFi. Like a phone. In other words as long as you have cellular signal from your carrier you can access the internet from anywhere. The Wifi models can only access the internet when connected to a wifi hotspot such as in your home, work or other location that has free or paid wifi.
With respect to your second question, as far as I know you cannot directly receive regular text messages (SMS) on any ipad, regardless of whether it is a carrier model or wifi only. It is not a phone. You can however receive and send iMessages which are to and from Apple devices only. There are also services such as "Continuity" from Apple which will allow you to send and receive SMS messages on your iPad by relaying them to and from your iPhone.
Hope this helps.
A:AnswerOther than the return policy of the retailer, there is no money back guarantee. There is a warranty on the iPad which you can upgrade/extend with their AppleCare service. While you are covered under warranty or AppleCare they will repair or replace the unit depending on what happened and whether it is part of the coverage. For example I don't believe the basic warranty covers you if you drop your iPad and break your screen. Regardless I don't believe there is any way you'll receive your money back once the return period from the store has expired.