With respect, there is a lot tripe in this summary. Don't be mislead by shoddy media reporting.
Most of the young people who voted to stay are students and/or have never worked. Half of the eligible young voters didn't bother to vote, no doubt quite a few were getting stoned at Glastonbury or the Download heavy metal festival over the weekend. They might be productive getting laid, but not in terms of the UK economy.
Northern Ireland is very, very unlikely to leave the UK. Scotland might have have a referendum on leaving but with current oil price it's far from certain they'll leave UK. The Scottish National Party is jumping the gun and making a lot of noise. I personally don't expect them to leave UK at the moment but no drama if they want to hold another referendum in a few years time.
As for that "petition", it is being investigated for fraud. Thousands of names are bogus. Unless there are more than 17 million genuine signatures from eligible voters, not people from other countries who don't have a vote, or virtual people with bogus names, it's a non issue. Even the left leaning BBC is reporting this:-
http://www.bbc.com/news/uk-politics-eu-referendum-36634407
You don't know whether the Leave camp is ill prepared or not. How could you? What is certain is that there will be a lot of discussions behind the scenes between EU member states. In due course, we'll know whether the Leave camp is prepared or not, but Article 50 has not even been triggered yet, and won't be for several weeks. UK is still an EU member state until they trigger the clause and then they have two years to negotiate their exit. Only democratically elected UK politicians will decide when to trigger the clause, not unelected EU officials.
Remain side is in meltdown because they never saw this coming. First, they didn't want to leave, and now they're desperate to leave and trigger Article 50! The UK will do that when it suits them, and not when it suits the EU.