Here is the sentence relating to the questions.

こんなうすぎたねえ車の中で また おあいできるとは思わなんだぜ。

1) Why is the 「は」included with the particle 「と」? I think only 「と」would be enough to be used with the verb 「思う」. Or the 「は」used for emphasizing?

2) I think 「い」is missing to make the verb 「思う」 negative, becoming 「思わなんだ」. Or is this an exceptional case or something of the verb conjugation?