Felicity follows Ben across the country and involves herself in his life despite him not wanting it. Not necessarily textbook definition of stalking, but definitely toxic.
Ben beats up another student he believes slept with his girlfriend. Not exactly a bullying situation, but the other student had no animosity with Ben. Ben is then targeted in an attack.
Season 1 ep 5. Felicity is talking to Noel in her dorm after leaving the party. Around 38min in.
Season 3 episode 4. Around the 37 min mark, Felicity is walking down the street the morning after a night of drinking. No sound but she runs to a garbage can.
Felicity is placed in a psychiatric hospital during the "time travel" episodes because the other characters believe her to be experiencing mental illness.
Usually no, but there are a few episodes that veer from the show's usual realistic depiction of college life. One episode is in the style of The Twilight Zone and ends with all the characters trapped in a shoebox. The final few episodes involve time travel that may or may not have been a dream.
Ish? There are two endings because of uncertainty about how many episodes would air the final season. One is bittersweet and one is... just bizarre. Neither are happily-ever-after endings.