The only questionable thing the spoiler guy said was
the adopted little bro, Orca, possibly getting Mpregnant or something like that, but the rest of the spoilers are pretty much there, if you used mtl the wrong pronouns may have confused you, but author made it clear that
Orca is an Otoko no Musume/男の娘 (Otokonoko) and become lovers with the mc, you can see it listed in the character info sheet too, doesn't help that the WN is tagged boy's love too in syosetu and kakuyomu lol
Something to add, if you used MTL, they usually translate
男の娘 as male-daughter, and more than often omit the male part, which leads to confusions, like for example in the WN synopsis disclaimer, ※男の娘キャラとの恋愛描写がございます。, it may get translated as "There are depictions of romance between male and female characters." (doesn't make much sense to put that as a disclaimer), but the correct translation is "there is depictions of romance with a otoko no musume", Orca being this Otokonoko in question and the reason is tagged as Boy's Love