I'm stuck with the problem of amarok refusing to play songs that have any non-ascii characters in the metadata, which is about 1/3 of my collection... A solution to that problem would be ideal, but if there is a good alternative (like amarok 1.x series) I would probably switch...

I had a similar problem in my install, the solution for me was to move to an UTF-8 locale.
The problem was that after changing the locale, I was not able to open any file with non-ascii characters in its name (at least with Dolphin and the KDE programs): the iso8859-1 chars were converted to garbage in the change to UTF-8. The internet gave the solution to that: a perl utility named 'convmv' that was able to convert the names to the proper encoding.

AlvaroG,
this does not sound optimal to me, why does amarok nor recognize other locales (encodings)? But it there is no better solution I may have to do the same...

Neither it was optimal for me (mind you, my native language is Spanish so I had to correct a lot of files after the conversion), but that was the only recommendation I found at the time in the internet. Some time has passed since, a better solution may be available.

You may want to do a search on dugan's thread "Beautiful fonts" and follow the links on his sig. Below is what was adapted from his instructions for changing system-wide locale:

gives a list of possible locales. Identify desired locale and input into file /etc/profile.d/lang.sh by editing line

To input other languages, check dugan's sig to enable scim. There's a bug with scim crashing firefox, workaround is to include line

in file ~/.xprofile

I found dougan's thread and his great home page (http://www.vcn.bc.ca/~dugan/) and combining the relevant info there plus a bit more googling resulted in the following solution:

1- make sure CONFIG_NLS_UTF8=y is defined in the kernel config
2- use append=" vt.default_utf8=1" (lilo.conf)
3- set LANG=en_US.UTF-8 in /etc/profile.d/lang.sh
4- set "iocharset=utf8" in the fstab entry for my filesystem (JFS), which makes JFS translate the filenames to/from UTF8 (ie no need to change filenames)

That was all, no need to rename files due to the nice feature of JFS, if you use a different filesystem then you must check to see if there is an equivalent option.

Now amarok2 can finally deal with all my music files and I got it to work almost like version 1.4 (what a waste of time this was!)