As for the EU holding the UK in check, that's not quite accurate. It's true that the current Conservative government under Cameron has been damaging to public services, but that's not always been the case over the past 20 years. The Labour governments of Blair and Brown, for all their flaws, weren't pursuing the same type of wholesale undermining of public services. As an added bonus, if you want the policies of the Conservatives to stop, leaving the EU is likely to divide the Conservatives more than most parties, leading to a weaker party at the next general election.
Lastly, the EU does not always act to protect the people of the UK. As an example, take a look at what happened to the UK fishing industry.
https://en.wikipedia.org/wiki/Common_Fisheries_Policy#Critic...
With the way the UK electoral system is currently set up, the extreme results it produces makes me very happy to have the EU to moderate things.
What the last 20 years shows us is that UK governments have systematically tried to erode workers rights, remove social safety nets and strip away human rights, and it's largely been the EU that has held it in check.
I fear what we'll see in the case of an exit, with a government no longer reigned in by the EU treaties.