I've been out of the phone loop since 2006. I currently use a Nokia 2330. I only use it for light personal use, and purchase prepay credit as I need it because I have an aversion to subscriptions. If I get a Lumia 520, will I be able to use it the same way, or is a certain amount of monthly data usage going to become inevitable with smart phones?

Basically, can I disable mobile internet, maintain telephony and rely on Wi-Fi for all (occasional) internet access?

Can the phone download all it's updates, apps etc. via Wi-Fi? Can it use it's GPS services without using up mobile data?

Sorry about the stupid questions.