You might find the works of Murray Bookchin interesting, he pretty much talks about the same things you are talking about.
He too wants to go past,"materialism" and investigate,"naturalism".
His essay,"Listen here marxist" might be right up you alley.
Which it's a fairly vulgar text, but I think he strikes a really valid point which is that the socialism of the 21st century isn't going to look like the socialism of the 20th century.
Which, with the emergence of the revolution in northern Syria, we might be seeing the beginnings of an eco-socialist revolution. Or the kurds just might get killed, idk, we will see, I think the ecology struggle might be too late, but I hope I'm wrong.
Anyway here is what I want to stress to you, the left is losing now, probably more then ever right? Like fascism might actually take control over the united states soon.
We can't be dividing the left any further than it already is. We need solidarity now, probably more then ever, if we're going to ever get anywhere. The Leninists are socialists, hell even the trots are socialists.
There are people on the left who have different ideas then you, doesn't mean they aren't leftists, they just have a different point of view. You need to understand where they are coming from, don't just shrug them off because the experiment in the USSR was messy. Reality is messy.
RE: The Futures of Democracy