Imma try Chinese here, even though it's not my native language lol. I know there are official translations, but those usually involve word plays and are sometimes cheesy, so I'm going to try to be more literal where applicable.
A Song for ×× － 給××之歌／給××之A歌 (I seem to remember Ayu said that the "A" stood for "Ayumi", so if that's the case, and the "A" is not just the article "A", then use the second translation.)
LOVEppears － 愛出現／愛仿佛 (I also seem to remember that by "appears" Ayu meant "appears to be", not "appears on stage" ... if that's the case, second translation)
Duty － 義務
I am... － 我是。。。 ／ 我存在。。。(First one: am = copula/linking verb; second one: am = indicating existence)
RAINBOW － 彩虹
Memorial Address － 悼詞
MY STORY － 我的故事
(miss)understood － （步）解 I'm sticking with the official here b/c it's just so perfect.
Secret － 祕密
GUILTY － 有罪(as in guilty of a crime/sin/etc.)／虧心(feeling guilty)
Next Level － 次場 (Lol, not too sure w/ this one, I would say 下一場，but that sounds too informal? But 次場 sounds really Japanese for some reason, I dunno haha)
Rock'n'Roll Circus － 搖滾馬戲 (I think that's the official translation too?)
Love songs － 愛情歌集
FIVE － 五
Party Queen － 派對女王
Love Again － 重愛 (If "love" here is a verb; dunno if this translation really works lol)／愛重來 (If "love" is a noun; this also happens to be the Chinese title of the movie
The Vow 
)
Colours － 色彩