Never hurt to find a partner for that or two, just to be on the safe side of things
Have few friends or a guildy greatly helps
But not necesarry, they are soloable even in ~400 gear, you just need to carefully dance around them and some avarage situational awarness, not to aggro a patrol or anything
Depending of the class, really
But as you said:
Both the War Campaign and cloak-chain, yes
Even the Wrathion part in Blackwing’s is like that