Thank you. Tried and seems to work, will keep testing and post any issues. What about 'System SEF' plugin? Does it have to be disabled?
Now about the URL creation. It is my understanding that if the URLs are not created properly, could this mean my categorization must be wrong (but it looks fine to me). Generally speaking, should I rely on JoomSEF's automatic URL creation, or it is absolutely expected to have to edit all URLs manually after creation? Obviously, as the site goes bigger, this can prove difficult.
To give an example: My site contact page, after JoomSEF was installed, has become like this:
mysite.local/en/contact-us/mysite-contacts/mysite-en
Whereas I would expect it to be something simpler, like:
mysite.local/en/contact-us (Just like it WAS before installing JoomSEF).
I also repeat that foreign characters (Greek in my case) SEF URLs still are not created. UTF-8 is enabled in Joomla, and also in JoomSEF. But it does not work. Yet, this is not my problem. I can live with just English characters in my URL, as long as the structure is satisfactory.