it looks to me like the title of this chapter is wrong. it's identical to another series's chapter this group uploaded roughly at the same time
edit: it's fixed
What angle? I don't see anything in the story that would be improved by her being stronger. In my opinion the whole point is that they have life experience and skill, but no strength. Give them strength, and you just have the original guy but visually different, which is a worse premise
looking at jisho.org, it doesn't seem like 海 is ever pronounced as "ma", but it can be translated as "marine". it's like half a kirakira-name, I guess? since the other kanji is pronounced rin.
Imo "marine" would be マリーン, not マリン, , though.
Yeah I know, and the characters should know, so why aren't the characters raising any eyebrows? To my knowledge she never told anyone about her past lives.