A canon teacher/student relationship (where the teacher was an emancipated minor posing as an adult) gets back together here where both parties are in their twenties.
No. However, there is reality subtext that must be mentioned here in that the reason the Splash Star mascots are not included and only appear in stock footage is because one of their voice actors passed away years prior; this is often brought up in the fandom to explain why Flappy and Choppy seem to have been recreated rather than just coming back.
While a parent starts to wall himself off from his child as he and his wife prepare to divorce, he does not flat-out abandon her. Karen's situation from the original series, where her parents left her with the butler and only returned once a year, is not mentioned, though at 29 years old she still lives in her estate with the butler.
A scene where one character stands behind a tree out of sight during another's party is often interpreted as such in bad faith by the character's haters. In the work itself, it is not presented as stalking, but as the character stepping back from the other (and he was almost certainly supposed to be there). The running plot device from the original series of the team stalking each other around town to figure out what's going on with them is not carried over here.
As the towns and city districts from the Washio-era shows have all fused together, the seaside town from Splash Star is often depicted and the ocean can be seen.