So I have tested the Dol Guldur faction where I had no enemies to look for some bugs and here are some:
When you form the two basic orc units they will lose access to necromancy power.
Necromancy risen dead can be refunded to the fortress costing 20 each (This may not be a bug but it can be exploited once you have the sorcery tower so you can make double amount of resources by training the basic orc units, turn them into risen dead and then decommission).
Necromancy will spawn a full battalion of risen dead even if it's used with a single orc unit.
Saenathra's sister cannot be decommissioned to the fortress (similar way cave trolls can't)
All heroes can enter the ruined tower except Khamul and perma summoned Nazguls by ring form Necromancer. Didn't test if summoned heroes like the undead troll would but I doubt it.