It's hard to pick a starting point on where to begin in explaining our disdain for gender-reveal parties, but the name itself seems like a good one, in the fact that it's a complete misnomer. You are not revealing the gender of your baby; you are revealing the sex.
DNA Polymerase is a polymerase that synthesizes a DNA strand ... so it's used in DNA replication. RNA Polymerase is not used to form the primer-that is primases job. RNA Pol is used during transcription to synthesize the mRNA strand. EK does a decent job describing a primer.
RNA polymerase is a general term for an enzyme that makes RNA. There are many different RNA polymerases. The basic transcription process is more or less similar in prokaryotes and eukaryotes, though the regulation of transcription is much more elaborate in eukaryotes.