1. I'm so sorry, I forgot to include the locales_tr file. Here is is. The translations you got are correct but rather formal, so I chose to use forms that are more neutral. Also, the translation of Brazilian Portuguese as ΠΟΡΤΟΓΑΛΙΚΗ is wrong -- it should be ΠΟΡΤΟΓΑΛΙΚΑ ΒΡΑΖΙΛΙΑΣ or ΒΡΑΖΙΛΙΑΝΙΚΑ ΠΟΡΤΟΓΑΛΙΚΑ (I used the former). And if anyone ever provides you with a European Portuguese translation, it should be ΠΟΡΤΟΓΑΛΙΚΑ ΕΥΡΩΠΗΣ in Greek.
2. Here is the translation of these words in the exact order you gave them: ΕΠΙΠΕΔΟ (in English it's abbreviated to "lvl.", so in Greek it could be shortened to "Επδ."), ΝΕΟ, ΕΞΟΔΟΣ, ΔΙΑΓΡΑΦΗ, ΣΚΟΡ, ΕΝΑΡΞΗ, ΕΚΠAΙΔΕΥΣΗ, ΒΟΗΘΕΙΑ. All words are in full caps, if you need them in small letters, feel free to let me know. Hopefully they aren't too long. Also I feel bad for making you draw all those graphics. Please, don't feel like you have too -- most people will be pleased there is a Greek translation in the first place, so those graphics being in English won't really matter to them.
3. I didn't really think about credits but you may credit me using my itch.io user name, arirangia. Thank you for wanting to credit me and also for making the game translatable as well as this port in general!