They do this is multiple episodes.... In s5 e17 one of the main story lines is about a teacher sexually assaulting one of the writers when he was 14, and people congratulate him saying what happened to him is "awesome" because the teacher was a woman.
S5 EP16 There is a storyline about Abby Flynn changing her identity to escape/evade an abusive previous relationship and she receives a death threat from the abuser
I believe it was s5 e1, but there is a scene where Pete talks about 'making love to my wife' but 'she was asleep so I didn't have to be gentle'. it then shows her from the chest up, appearing to be asleep and looking like she is participating in sexual activities. It's not explicit but could be upsetting
There are several mentions of one of the character's father who dies due for a heart attack during the whole show. Starts at season 2, during "The Collection"
Also, Jack's mother dies on-screen in the last season.
Lutz gets sick sometime in s1 when Liz gives him responsibility, s1 ep8 at the end Tracy does a skit and v*s everywhere, s2 ep5 when they flash back to kenneths party Liz v*s, s2 ep15 Kenneth v*s after running to turn in his Olympic application, s3 ep8 Kenneth v*s at beginning with flu, people get sick throughout, fake v on Frank’s death s3 ep 13, s3 Liz v*s some time when meeting Jon hamm, s3 ep16 jack v*s after laughing (near end), s4 ep3 Liz v*s after getting food poisoned, s5 ep10 Tracy’s thanksgiving skit at end, s6 ep19 after being stuck in Tracy’s dressing room and Kenneth describes history of live television, s7 ep 11 hobo v*s on Lutz
Season 1 episode 12 features an "inbred prince" with comedy centered around puppet limbs in a wheelchair, being too weak to blow out candles, and fatal allergies. Season 1 episode 20, It is suggested that a studio lawyer promotion is given to someone because he is black and in a wheelchair. In a later episode someone mentions in passing that he thinks the guy is faking.
Tina Fey is often referred to as if she is overweight. One of the writers is presented as having a thyroid problem and teased about eating. Jenna gains weight over the summer and it's a whole thing.
On three separate occasions that I remember. Apparently, the episodes involving blackface have been suppressed in light of the George Floyd protests in 2020
There is an episode where Liz goes on a date with a man, and right before they kiss they realize they’re related. They are somewhat distant cousins, and they decide to not pursue anything further sexually or romantically, and they end the date immediately.
Jane Krakowski wears a fat suit to indicate that her character has gained weight. This is a central plot line in the episode. She uses the catchphrase "me want food" a number of times.
When being fat no longer serves her she immediately loses the weight/takes off the fat suit
There is an episode where two character are on a plane together and they experience bad turbulence. They think the plane is going to crash but it does not.