temp will vary depending on the material, color, and the hotend... the stock SD4 hotend ran much cooler "reported" temps than the E3D does
While not an absolute necessity, a fan is quite useful for printing PLA. It does depend a little on what you are printing, too... fine details and overhangs definitely benefit from a fan - larger, less detailed things with few or very shallow overhangs, it is not a big deal
SD4 #1 - Lawsy carriages, E3D v6, Rumba controller board, mirror bed plate, X motor fan & upgraded PSU & Mica bed heater
SD4 #2 - basically the same as SD4 #1 now...
Folgertech 2020 Kossel kit with reprinted plastics and top mounted bearing spool feed
Folgertech FT-5 - in progress... (sold the 2020 Prusa)