たしかに/なるほど~かもしれない => might; perhaps N3
Speculation
など~ものか => No way... N3
Position, perspective
どうも ... そうだ/ ようだ/ らしい => It seems, probably N3
Speculation
どうも => Confused, bewildered N3
Emphasize
どうも => Not sure... N3
Vague
もしかすると/もしかしたら~かもしれない => perhaps; maybe; perchance; by any chance ~ N3
もしかしたら…か => perhaps; maybe; perchance; by any chance ~ N4
Speculation
かどうか => whether or not ~ N4
たらどうですか => why don't you; how about ~ N4
Invite and advise
どうせ (のこと) だから => Because eventually have to ... N3
Invite and advise
どうも => Used to greet N5
How to say the beginning
どうしても => no matter what; at any cost; after all ~ N3