I recommend using the Biker outfit for most of the areas. The names of areas you have found show up on your pause screen map. Rather than using the compass on the map, I've oriented directions as the map appears on your pause screen (N is up, W is left, etc)
Level -2:
Basement Bar (SW corner of the map)
Boiler Room (East side of the dance floor. If you don't have a keycard, enter at the NE end of the dancefloor backstage and work your way back south)
Dance Floor
DJ Booth (backstage, North of the dance floor)
Hirschmuller's Office (North of boiler room/DJ booth)
Level -1:
Pipe Room (West side of the dance floor, tech area "backstage")
Projection Bar (Bar at the end of the SW staircase)
Level 0:
Back Entrance (North of the club, enter from the west side of the map, opposite the crane)
Biker Hangout (Northeast corner of map. Rooms on the southside of the garage)
Chill Out (Outdoor hangout area, at the NW corner of the club)
Club Entrance (Indoor section of the queue)
Club Holle (Queue area outside of the club)
Drug Packaging (Center of Biker garage)
Garage (East side of the Biker garage)
Juice Bar (North of Chill Out area and South of Biker garage)
Radio Tower (Outside of the fenceline between the original bus stop and the club)
Red Toilet (NW corner of club)
Warddrobe (North of club entrance frisk area)
Water Channels (SE corner of map. Pipework section outside, east of queue area)
Level 1:
Grow House (Center area of Biker garage)
Level 2:
Sniper Nest (SE corner of Biker garage)
Level 3:
Bypass (bridge connecting Biker garage and club)
Level 4:
(no areas)