Earlier quoted context omitted.
Living in Romania right now, but I'll ping you when I'm back in NL (I go there at least once every few weeks), Clojure seems to be the most approachable from the languages you list. Besides your listed reasons mutable state is becoming a bigger and bigger bottle neck as the number of cores goes up and that's why functional programming is becoming more and more important. It also makes programs much harder to write in…
This may be my biases speaking but I'd say Scala is a more approachable option than Clojure (and more popular, and has a first-class web framework in Play). It keeps more of the traditional OO style and syntax - you can use scalaz and write scala that looks like Haskell, but you can also write code that corresponds line-by-line to java, whereas with Clojure you're forced to make a more immediate leap to the lisp-styl…
Finally, I must say that while Scala does indeed have a first-class web framework in Play, web frameworks are first-class objects in Clojure. Joke. Sort of. I personally do not want to have a monolithic pre-packaged web framework to bow down to; the Clojure community is a community of hackers, we like to make things out of other things, and to take things apart. Clojure and the work of its community allows me to compose my own web framework as needed very very quickly–and to drastically change it just as fast. I'm not saying you should stop doing what you like to do, but if you gave Clojure a chance...dude: it's addictive.