If the next person to write The Master has any sense they'll forget the drumming. Doesn't even make sense in the context of what RTD put it there for. Hearing drums makes you wanna kill innocent people? Da fuck?
If the Sontarans can invade Gallifrey then I'd say the Daleks are a decent foe for the Timelords,
The Sontarans invade for like 5 minutes before being stopped