It's one of the trickiest decisions for anyone to make. The problem is that there just isn't any certainty of outcome for staying or leaving. Nobody can definitively say "it will cost £xbn/xx million jobs if we leave." It's just a great big hole of unknown. Nobody even knows what kind of deal can be struck about leaving. How can you make a decision whether to vote to stay or not if there isn't even a plan in place for what happens if you vote to leave?
The only thing you can really do is look at if the benefits of staying in the EU are enough for you to think it's worth staying. Forget the rhetoric, look at the ways the EU benefits you. I guess the most obvious is giving people a broader justice. It's possible (to a degree) to go over the heads of legal powers in the UK to try and get resolution. Other than that, I don't really know of much else? I'm sure people have looked into it in detail?
Balance that with the negatives being in the EU brings - things like vulnerability in cases like the Greek financial crisis - and there are your answers really. In terms of impact, we won't know until we leave what impact there realistically is.
From a personal morality point of view, I believe that the world should be getting smaller. We should be trying to unite in a single "people", rather than trying to add walls and barriers. We can't do that if everyone remains insular and alone. The problem there is that people are by nature selfish, so some member states will use the EU to bolster themselves at our cost. The question is, should be lead by example or tell them to **** off?
I don't have answers and haven't decided yet how to vote. Keep the status quo or take the risk? However, it's vital that everyone does enough research of both sides to make an honest decision and to vote. It's vital that everyone has a say in this matter and it's as well thought out as possible. Either decision will have a huge impact on the future of the country. This isn't a political decision - it's not voting for favourites - this will affect everyone 10, 20, 30+ years down the line. It's important to me that everyone votes one way, and in the best educated manner possible.
I doubt that will be possible as both sides will be too interested in mud slinging and throwing around their own agendas - but it's worth trying to cut through it...