I don't know if this is default in Firefox, but in Chrome you can just right click and "translate page to English" to read the Italian posts. It will still be a LITTLE wordy, but for the most part it's easy to understand.
As for what should be done about the intense divide in languages used here? I suggest encouraging correct spelling and grammar. That way, translations will come out correct (if the translator doesn't recognize a word because it's misspelled, it won't be able to translate it), and it will also be able to rearrange the sentences properly.
We have the tools are our disposal to talk plainly to our different-tongued brothers, so we should use them instead of raising it as a true issue.
...Having said that, having two separate forums based on language is readily possible if someone wanted to do that. But I like having the information from both nationalities in one place(after all I can just right-click translate the page to read it!).
There's my 2 cents on the matter.
Happy Hacking.