There are many phrases that don't tranlate at all, and many people who misuse the translator to the point of making it useless.
You give a great example in your post. {Right}? is a direction. It cannot be translated to into the meaning you want to give it.
http://wiki.ffxiclopedia.org/wiki/Auto-Translator:_In-Depth/All_Categories Here is one example from this page:
"Reward:" "Récompense:" "Belohnung:" "houshuu:"
Notes: This autotranslation was added in the April 18, 2006 patch, intended to clear up a common misuse by English-speaking players. Players would often autotranslate the Beastmaster ability "Reward" when offering compensation for assistance. However, on the Japanese client, the name of this job ability involves feeding or taking pity on a pet, and the results were often off-putting or insulting. "Reward:" attempts to clear this up by giving English speakers a more proper option in the wording they are used to seeing. "You can have this" has also been acceptable.
*End*
This should be required reading for those who trying to communicate properly. Also, with just a few quick key strokes, you too can learn Japanese!
"You're welcome" =
formal = "dou itashimash*te"
informal = "ie ie" meaning "no problem".
Still, you make a great point that some basics ideas such as {Tank} and {Healer} would be useful. {Ninja}, {Paladin} and {Looking for members.}{Healing Magic!} would also work for those. I'm not sure SE would want to fully recognize the slang word {Tank} by adding it into the translator. They have this thing were they pretend all melee jobs could fill that role.
I'm curious just what improvements will be made to the translator. Hopefully, some of your ideas have already been implemented.