甲斐がない/甲斐(も)なく => it's not worth one's efforts to do something N2
甲斐がある => It’s worth one’s efforts to do something N2
しかし => But, nevertheless N5
Change the subject of the story
もし~としても/もし~としたって => Assuming; Even if ~ N3
し~し => and; and what's more ~ (emphasis) N4
...し, ...し, (それで) ... => Because... and..., so... N4
List
しかしながら => however, nevertheless N2
Things do not match the prediction
し(~し) => and ... N4
Cause and Effect
...し, ...し, ...から => and; and what's more ~ (emphasis) N4
Line up, list
…たりしたら/しては => ... Such as N3
Demonstrate by example
...し, ...し, (それに) ... => besides; in addition; also; moreover ~. N4
List
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