Most of those things seem pretty reasonable to me, even those that I do not agree with.
There's a lot of naivety as well.
He wants a negotiated settlement for the Falklands eg. The islanders don't want it and the Argentinians won't be satisfied without it, so why would that be a good deal for Britain?
...
The Falkland Islands had a poll in 2013
Out of 1650 people
1517 people voted
1513 voted that they wished for the status quo to remain
(3 against and 1 invalid)
How could he possibly negotiate for any kind of joint control with that kind of mandate for the status quo?
Most of them seem fairly reasonable though with problems that mean they just wouldn't work.
For example ending austerity by, "higher taxes for the rich and a crackdown on tax avoidance and evasion while tackling "corporate welfare" and tax breaks for companies" - even if you ignore the fact that this could/would decrease wealth creation (as would the maximum wage idea) - I'm pretty sure that you could do all that, and still be left with not enough money to fund it. What's the plan after that? I suspect that it might come into the higher taxes for the rich part - just with an increasingly wide definition of 'rich'.
Similarly, it's a great idea to replace student tuition fees with grants but the only way to afford that would probably be to drastically reduce the size of higher education. I wouldn't be wholly opposed to this - but can you really see any government saying that actually they want to it to go back to only 10% of school leavers going to university?
If they have good enough press and avoid some of the most unelectable ideas I might worry they could have a chance.