1. Schengen itself isn't a problem for us because we are not part of it. Schengen is a major problem for the countries that have signed up to it. Us leaving the EU won't change that. And as you are fully aware, the problem of terrorism isn't just confined to EU nationals. It's to do with Middle-East nationals - for whom an effective Schengen would be an irrelevance - and home grown, British nationals - for whom again, an effective Schengen is an irrelevance. If you want an example of an EU national terrorist, have this one: if an Iraqi or Syrian terrorist wants to travel to an EU country, wait five years, apply for citizenship, gain that citizenship, and then travel to the UK and blow himself up, I can't see any way of stopping that, either inside or outside the EU. If you can see a way - and please don't just repeat 'effective border controls', as this guy's been a model German citizen for five years - please enlighten us all. I know many people in Government and the security forces that would love to hear your insights.
2. If the UK votes for Brexit on those two issues, then it'll be clear that it was a vote based on fear and ignorance - and it's a vote that will have been utterly ineffective. Whether or not we are in the EU makes no difference to the ability of a determined terrorist to enter the country. I really think that you understand this as well as I do.
3. Yes, we're one of the world's strongest economies. Why would you risk that by throwing away the trade relationships with our biggest trade partner that has got us to that point, and then hope that something nearly as good can be negotiated - and negotiated by the very people that you feel have been poor negotiators up to now?