The creatures and Otherworld in Silent Hill 2 and 3 are both created by the psyche of the protagonists, James and Heather respectively. It's SH1 and SH4 where the protagonist is just an everyman who becomes trapped in someone else's nightmare (Harry is sucked into Alessa's Otherworld in 1, and Henry becomes trapped in Walter's in 4).The OP misrepresents the SH3 nurses, IMO. They are still effectively freaky, and it doesn't necessarily need to imply that Heather is into women. It could represent that she's intimidated by sexy women, standards in society, etc. But in any case...
Isn't it just in SH2 that Silent Hill is a representation of the protagonist's psyche? I recall SH3 being someone else's representation of their inner demons.