What I’ve done to help in my own decision is “remove the immigration argument” from the equation.
Even if we voted 100% OUT - it would take a long time to roll back those already on their way here, revoke the benefits of all those already in work - effectively deporting them (cheapest way to do it, mind!) and replacing missing staff with enough workers so that the job still gets done…
This last bit is a sticking point. There’s no way that firms en-masse will just pop up and say “All our immigrants have left, so we’re doubling hourly rates - can you start next monday?”
Pigs might fly… Into Cameron’s mouth more likely than through the air.
Firms would advertise at the old hourly rates, no takers, firm starts to lose money due to reduced capacity - a new recession commences… The downside of the “OUT” campaign that is spoken little of by anyone with any economics know-how.
For stability’s sake then - current immigrants need some kind of amnesty. Benefit cuts will not be retrospective, but any newcomers as of say, 1st April 2016 would NOT get any benefits under any circumstances… Hey presto, the immigrant of the future is someone who’s coming over here to BUY, then FIT OUT, then STAFF UP, and finally RUN a factory, perhaps one that’s been mothballed for a while…
Now that is GOOD for the economy - no one can deny it.
Thus, that issue dealt with - let’s move onto the actual nuts and bolts of leaving the EU…
The EU is NOT going to put actual trade sanctions upon us. This would be an act of war, and would never be countenanced. They MIGHT impose tariffs upon us, but that would hurt them more than us all the time the Euro continues to be artificially propped-up whilst the Pound gets sold off at the slightest new bit of perceived “bad news”… So we sell to the rest of the world instead (to avoid EU tariffs) and BUY stuff from the rest of the world - seeing as EU stuff now has surcharges upon it. The EU lose, and Lose. We get ? and ? - It can’t very well limbo below Lose/Lose though - can it?
Trade routes with countries further afield have a history of being rather more lucretive than doorstep trade in any case.
The “three million jobs that get lost if we leave” is a total lie. SOME people might have SOME business with the EU as part of their many other duties. The number of UK workers that are entirely employed by the EU in a position that will no longer exist post-Brexit - is what? - 4 figures? Maybe the low five-figure range. Officials.
Then there’s EU drivers not being able to drive on our roads any more without paying hefty entrance charges like we already have to pay as tolls everywhere out there.
Erm… That’s a whole lot more jobs for Drivers based in the UK!
Then there’s Tourism… The Euro is overpriced compared to the pound at present. This makes “coming to Britain as a tourist from the EU” look quite cheap. If the pound slumps after Brexit - it will be cheaper still.
Tourism GAINS.
Our own citizens, finding the EU rather expensive to visit now that the Euro is high and Sterling low - decide to take more “Staycations” which helps our balance of trade deficit. Foreigners spending money here in the UK helps too of course!
Would “leaving the EU weaken our position in NATO”?
Personally, if it did - I would not give a hoot. I’m one of those who thinks that reducing relations with NATO, the US, and even Israel - isn’t a “downside” at all… That in mind, do we give a hoot what THEY think of US?
Not if the worst that can happen is how frosty things have got between Britain and Russia right now… 
Most people don’t care about Socialism/Federalism, or even Capitalism. They just want more of the things they like in life, less of the things they dont like - and everything kept in order by decent strong laws strongly enforced in the public’s favour. Something else that could improve if we had the money to spend on home infrastructure, home jobs like policing, and using fine revenues to pay for even more traffic enforcement officials in particular. The public on the road take the ■■■■ enough as it is. 