まず...だろう/ ...まい => Surely... N2
Speculation
うと~まいと,うが~まいが => Whether or not A (is/occurs) N1
Based/focused/depending on
いまさらのように => Now... again... N2
Time
ようと...まいと => whether or not; regardless N1
Innocent
~ようが...まいが => whether or not; regardless N1
ようか~まいか => whether or not; considering options N2
ましょう => let's ~; shall we ~ N5
しまいそうだ => It seems like this is about to happen N3
Speculation
いまにも ... そうだ => It seems like ... at any moment now N3
Short period of time
ますように => making a wish N3
~きわまる/きわまりない(~極まる/極まりない)      => extremely; very ~ N1
てしまう => Did something N4
Secondary Verb