you think that's cute?
harakiri (腹切) is seppuku (切腹) backwards
Also in Chinese, "我有頭痛", tho "我有头疼" is often used in mainland speech.
"我有頭痛" sounds very Taiwanese. This usage of 有 is an artifact of Taiwanese / Minnan dialect. The Standard Mandarin (普通话) way to phrase that sentence is just "我头疼" or "我头很疼". Also like you said, 疼 sounds a little more mainland and 痛 sounds a little more Taiwanese. A general word for "pain" is 疼痛, they are really synonymous.
頭が痛い (atama ga itai)
頭痛がする (zutsuu ga suru)