These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Angst? What Angst?: Paquita seems to take her dog being eaten by Lionel's mother quite well.
Ensemble Darkhorse: Everyone loves Father McGruder, even though he has a pretty small role.
Freud Was Right: In the end Lionel's mom, turned into a huge monster, captures his son and puts him into her huge belly; he later rips her apart from the inside and emerges in a pool of blood, in an almost-fetal position.
And note that this is just a more over-the-top version of the ending of Bad Taste. Jackson may have some mother issues...
Moral Event Horizon: Turns out Lionel's mother crossed this long before she turned into a zombie, drowning both her husband and a woman he reputedly had an affair with in the bathtub. And then fabricated a lie that pushed blame onto Lionel.
Based on the picture of the attic, it seems that Lionel's mother isn't even his mother and that the "mistress" is his real mother
That seems like a hell of a stretch. The way the pictures are presented indicate Vera was snooping on the dad, and Lionel's flashbacks show the woman in the photographs being held underwater along with him.
Squick: When guests come over to see his ill mom, they have a relatively uneventful dinner until his mother's ear falls off and lands in the custard. She then absentmindedly eats the custard with the ear.