Yep, I also read that as おぅ またなぁーっ.
A small vowel at the end of a sentence indicates a long training off sound. The small ぅ makes this a long Oo sound that drops off. I don’t think it’s a word, but just an exclamation without much meaning. See also the first panel on page 7: ふぅ
The small っ at the end of a word or sentence indicated that the sound cuts off abruptly. See the second third panel on page 1: えっ？
I’ve never seen this combination of 天気予報 and め before. Some Googling turned up some hits in blogs and such. The context is usually when the weather report is unreliable. Maybe it’s an abbreviation of ダメ (no good)
p.7
It is related, as far as I can tell. But ブラつく has its own entry in the dictionary as a verb. It can be written either as ぶらつく or ブラつく.
See buratsuku - Jisho.org