You want answers but you won't research all the materials about it.
Umm, okay.... Not very "logical."
You never read any technical manuals or schematics or books for any other Trek vessel? Ever?
Anyway, while I sense yet another attempt at picking the fun out of this movie....
The Narada, as seen in the comic Star Trek: Countdown, started out as a relatively simple and small craft. With the implementation of the reverse-engineered Borg components, who is to say that the changes to the vessel "make sense?" The technology apparently caused the spires to multiply, grow, and the mass of the vessel itself increased as a result.
I'd venture to say that before her change into a monstrous killing machine, the "pointy bits" could very plausibly have been a tool for mining operations. They may have even had something to do with the dangerous orbital and suborbital conditions of the mining process.