I find it unbelievable that this is even up for debate. WTF is the government doing even having a referendum? We vote governments in to make decisions for us and not to cop out when some right wing feckwit makes a fuss.
Out would be a disaster.
The lies and utter bullshit from the leave campaign is astounding as is people's willingness to believe some anecdotal bollocks over actual evidence and information. Lets deal with the bullshit first.
1) Linking sexual trafficing/sexual abuse to Britex as I see every day on various social media is not only ludicrous but downright insulting to the victims. The Rotherham case is frequently used as an example involved as many as 1400 victims over a decade was a failure of council in their care homes and the perpetrators were either British or non-European. So nothing to do with trafficking and nothing to do with free movement of labour in the EU.
2) Refugees (almost none of who are European BTW) get preference for public housing and higher rates of social benefits. No matter what a good friend of your Aunt's dog groomer said this is bullshit. It would be illegal as these are governed by legislation not anecdote.
3) Migrants are apparently stealing our jobs and sitting on the dole taking our hard earned money. Make your fecking mind up. Which one? The actual evidence is that people who move to the UK from elsewhere in the EU give a massive net gain to the UK as on average they earn and pay tax then go home if there is no work. Refugees, if allowed to work, also claim relatively little and tend to both work hard either doing the menial jobs we think are beneath us or setting up small businesses. If we leave the lazy dole bludgers who are the real problem will remain as they are British and the rest are systemic failures of government employment policy over 4 decades.
4) The biggest lie is about the cost of membership. Britex quote a figure that excludes the rebate we negotiated decades ago. The actual cost is less than other non-EU Scandanavian nations pay just for economic access. In other words we would end up paying the same or more for far far less. Madness. And this is without taking in to account the money we get back billions of which has been spent in Northern Ireland and the NE amongst other places. The actual costs is very small indeed compared to the benefits of membership.
5) The economic arguments for exit are also laughably wrong. We do the vast majority of trade with other EU nations. We do more trade within the EU than with all other countries combined. Individually we do more trade with Holland, Germany, France and Ireland than we do with China. To lose free access to our biggest market not to mention that many of our trade deals with non-EU nations are with the EU and not with the UK is economic suicide. All these agreements and a new one with the EU would need to be negotiated and these things take years, often decades.
6) Anyone want to work in Europe? Get in line with all other non-Europeans for a work visa that may or may not be granted. Want to retire to the sun? Sorry but you can't buy property, claim any social benefits and you will have to pay the full economic costs of medical services. Until your visa expires that is.
7) Who are you going to trust to look after employment law? It is bad enough with things like zero hour contracts and reduced/removed penalty rates but remove EU law and things will get much much worse.
Of course the EU could do with some reform but leaving is throwing the baby out with the bathwater. The UK hasn't been a world power since WW2 - get over it. Leave and we will be a banana republic. The Zimbabwe of Europe.