Is the word considered a curse? Can 馬鹿 be an alternative?

Hai, "LET ME TRY TEACHING YOU HOW TO SPEAK INSTEAD OF WHAT TO SPEAK". Hope if you are in a real & serious search of a right English language practicing partner, Here's to share my time with type or voice chat through skype only. I come forward to help you with free of service & meet me at [email protected]

We write アホ that's not only Katakana. We write it by Hiragana, too. And it's not slang. あほ is 阿呆 by Kanji. But anyway, I think that you shouldn't use this word so much.

I see. So far example テレビ. I am a little confused on why アホ is written in katakana though. Is it because it is slang or does it actually derive from a foreign word?

No problems, we Japanese often use "Japanese English" and clipped words. I often don't know whether it's correct or not.