Is there something wrong with saying 千万不喜欢 to mean I absolutely do not like something?
As other answers pointed out, 千万 is usually used as a warning. 千万 typically implies a reason why you should or should not do something (Otherwise you would suffer a certain consequence). E.g. 你走路时千万要小心 (否则很容易摔倒).

If you want to emphasize the strength of your dislike in your example, you can say: 我真不喜欢抽烟。// I really don't like smoking. 

You can use other words to express your dislike too, such as 讨厌. E.g. 我讨厌抽烟。 Add more emphasis: 我很讨厌抽烟。 ,  我非常讨厌抽烟。 or 我特别讨厌抽烟。 The extremest could be 我真的是非常，非常，非常讨厌抽烟!!!

P.S. In English, "I absolutely do not like something" is probably an idiomatic way. But when it's translated into Chinese, it might not be idiomatic any more because both languages expresses things in different manners. In this case, a direct translation would be: 我绝对不喜欢抽烟. But the sentence's rarely been said in practice. You are more likely to hear 我一点都不喜欢抽烟 from a Chinese speaker.