1: "can we get people with a broad range of views on the left to work together to bring a bit of hopeful energy to the political scene?"

I dare say that you could try, but as usual it would ultimately end in failure, as the last time this was tried was. Every experimentation in "socialism" starts out well supported with everyone yelling how great it will all be, then those actually running the show find themselves confronting real problems that require real solutions which may prove to be highly unpopular so the problems get ignored or "fudged". Then when it all turns to shit (As it did in 1951; 1970; 1979 & 20104i.e. those responsible for running things} weren't really "socialists" after all.

2: "will scots now condemned to westminster rule for the foreseeable join with the more progressive elements south of the border?"

Ah GUEST,achmelvich since 1999 no Scots have been condemned to Westminster rule - they have had their own Parliament which has been almost exclusively "left-wing" and "socialist" in nature. That devolved Parliament was granted tax raising powers from its inception but no Scottish Government whether Labour or Scottish Nationalist ever saw fit to use them {Much easier to blame Westminster which is what Jowly & Co did during the Referendum Campaign} - which kinda begs the question "If you don't use the extra powers you've had for 15 years, what the hell are you going to do with these additional powers being called for now?"

The additional powers will never be used to increase tax revenue as that would make the elected government unpopular with the electorate - No good just saying "Tax the Rich" because then the rich just move taking their money with them and you end up taking in less than before - your tax regime must not only be "fair" but it has to seen as being "fair to all" (Top 10% income bracket {The Rich} pay ~45% of the total tax revenue collected from income) squeezing them more is generally not a good idea short, medium of long term.

Between 1997 and 2010 there appeared to be a meeting of minds between these socialist progressive minds north and south of the border - it resulted in the country {The UK} going from being fairly well positioned financially and economically to almost being totally ruined.   

3: "is this an opportunity for the greens"

The Greens as partners are "toxic" for any potential political party - take them onboard and you end up getting roped into daft deals that cost a fortune in terms of money, businesses and jobs.

4: "especially with the labour party giving up any pretence of being a left of centre party?"

There you go - Not real socialists - but I am pleased that you have met and have recognised that new phenomenon - the Professional Politician - capable of sporting any campaign rosette of any colour, never held down an actual job in his life, and is only interested in gaining power by whatever means, subterfuge or promise (None of which he ever intended to honour) then is totally focused on holding onto power irrespective of the damage done to the country in pursuit of that goal - Thus Gordon Brown sold off the Gold Reserves of the UK and raided the Pension Funds (To buy votes) allowed unchecked mass immigration to ensure there would be a sufficiency of Labour voters at the next election.