My opinion is that a non-native speaker of English who begins to routinely use English after about 12 years old will never speak English like a native. I do not pretend to have researched this question; my opinion is simply based on my experience of having spoken with thousands (not an exaggeration) of non-native speakers of English residing in the United States. Even skillful non-natives will always have at least a faint trace of a foreign accent, and will sooner or later make a grammatical or lexicological mistake that a native would not make. In addition, native speakers of a language will use words and phrases from their nation’s cultural patrimony; and it is unlikely that a non-native will be as familiar with that patrimony or those words and phrases. However, I do believe it is possible to learn to speak a foreign tongue fluently, with an <em>almost</em> imperceptible accent, and with very few grammatical or lexicological mistakes.

Of course! It just depends on the person's condition. For example, I moved to the states when I was 7 and have been living in the states ever since. Although I was born in another country, I speak the English language much better and much more correctly than a native speaker. So yeah, it is definitely possible. Though if you are an adult, then you'd have to put a lot of effort and practice in it to perfect your accent. BUT YOU STILL CAN SUCCEED. Good luck!

English is my native language and I am looking to learn arabic. I was wondering are you still searching for a language partner? 

It's possible if you are living in America specially if you are living there since you are young.