Cell phone networks have versions. 3G version has better connectivity than 2G, it also supports higher data speed than 2G. 4G is also available, only phone which are very pricey support this now, it'll come down by the time 5G is introduced.
Nokia Asha phones are not smart phones, they allow you to do almost all the things a smart phone does. But what exactly are you requirements. From the OP, it seems you want a phone with QWERTY keypad, you'll probably want to use it for emailing and browsing? Buy phones with QWERTY keypad only if...
I don't know about this phone. But you should have kept the I phone and gave this to your wife. Computers are always connected to power so you won't have such problem with them. Phones are different and good ones usually last long enough to give a satisfying experience, anyway wait till next...
Then go with the Sony 1. Or a buy phone costing Rs. 9,000 and a camera costing Rs. 6,000. Camera phone in that price range don't have good low light capture.