Yeah the resistance even with clutch pulled in is normal, esp when its cold, sometimes u might not even be able to push the bike.
On 450r's the silver/grey oil from the clutch is normal. I would think on a 400ex if u slip the clutch a lot it would be no different, but it shouldn't be extreme.
Also possible that the clutch springs are shot.
05 450r
Motowoz LT F&R / SMC +3 / Elka Pro Dual Link / RPM / Flexx / Rath / Douglas
DRG Head / Ferrea +1x4 / CP 12:1 / 05 HRC Cam / HR +3 Balanced&Welded / DRG 43.5 FCR / DASA Classic