You may need a visa because we wouldn't be part of any free movement of the EU, the Swiss have their own agreement in place and it would be nieve to assume that we would automatically get the same or any kind of trade agreement, the big players in he EU don't won't it to break up, if we leave then allowing us to pick and choose what we want would only encourage more countries to do the same, it's in their interest to block us off from any kind of good deals. You can work more then 48 hours a week if you actively sign out, if you don't then your employer can not force you to, leaving the EU means the government in power can retract that and your employer could force you to work however many hours they wanted.
I'm actually on the fence on this, there are pros and cons to both and I'll need to see more information before I can decide. What I don't think I've seen anyone mention is that if we leave the EU it will certainly result in a second Scottish referendum and give the SNP the momentum they need to win, so almost certainly voting to leave is also voting to break up the UK!