Translation of "Casually" in Japanese

As casually as some of you may think about the weather.

何気なく天気のことを考えるのと 同じ程度なんです

He picked up the newspaper and glanced casually over the front page.

彼は新聞を取り上げて何気なく１面を眺めた。

Unless you prefer talking like this, you can speak to me casually.

- この話し方が好きじゃなければ、カジュアルに話してくれていいよ。
- こんな喋り方が好きじゃないなら、タメ口でいいよ。

He was an amiable fellow, but had a certain reserve that he would not let you casually trespass upon.

彼は愛想のいい奴だが気軽に踏み込ませない一線を持っていた。

We were talking and I casually asked about something, and I wasn't really interested, so it doesn't matter to me if you speak or not.

俺は話の流れで一応聞いただけで特別の興味はないので、別に話しても話さなくてもどっちでもいい。