I have a fairly complex proposal for a new currency which addresses numerous flaws in bitcoin.
Is there an alternate venue to discuss crpytocurrencies which is not forum.bitcoin.org?

The forum is generally hostile to posts that point out problems with bitcoin and propose possible solutions.
A new discussion platform would be a good first step to generating a sustained flow of innovative ideas.
The new platform doesn't need to tied to any particular project, but it should not be focused on new projects rather than bitcoin.

Is there anything like this around yet?

In the meantime, I will work on a blog to introduce my own proposal in moderate detail (not done yet).