There should also be more interactions between the non-human races of the Alliance, especially between Night Elves and Draenei, dwarves and gnomes (both to show the frienship between the Bronzebeard and the gnomes, but also the hostility between gnomes and Dark Irons for their alliance with Sicco Thermaplugg), draenei and gnomes with both species working together in magical and technological projects, Night Elves and Tushui Pandarens given the history and former ties between the two races, Kaldorei and Wildhammer dwarves over their love and respect for nature, the Jinyus with everyone, etc...
If we go to the topic the whole concept of "an opponent of the government" of the WoW is to be an outcast.
The difference is that Maiev has an already developed motif and a name. Fandral on the other hand was born to die. Highborne and Renegade Kaldorei are literally pariah.
Let them watch with a crisis of faith, do not think for a second in Elune and in having more Anduin interactions. When the Kaldorei are what really help him and his race. Is pathetic.
I would argue that his arc, in Cata was pretty interesting and the Flame Druids have had lots of potential. Heck the fire cat form still looks absolutely awesome and i kinda wish they would expand upon it with more of the Kaldorei characters. In a time of strife people are prone to gravitate towards extreme viewpoints so these nishe groups could make sense, after all Tyrande and Malfurion failed to defend the tree they didn't even want to begin with and continuously send Kaldorei to distant whoever the hell knows where, while they rarely get any help at all, with their homefronts, even when their home is up in flames.
If I could rewrite Fandral Staghelm and the druids of the flame story I would make it that Fandral did become the first druid of the flame after studying the Firelands and the more benefic effects that fire and volcanoes can have on nature such as purging poisons and allowing plants to renew themselves, and him also thinking that the Night Elves needed to be more agressive and find new weapons against the Old Gods' servants and the Horde.
His methods would have clashed with Malfurion and Tyrande's but he would have stayed on his people's side and become more of a well-intentionned extremist like Illidan. And eventually Malfurion and Cenarius would begrudgingly recognise the value of the druids of the flame.
There is no alliance story. they are just a counter piece And or punching bag to the horde.
Though Fandral Staghelm was, although I have already expressed myself on what his role and development could have possibly been if he wasn't turned into a villain.
On Stormwind's side we could have seen what exact role and power the house of nobles have and to what degree they could possibly oppose or limit the king's power without it being just a good vs evil or honnest good ruler vs corrupt noblemen scenario, same for the noble houses in Kul Tiras.
After rereading Asoiaf I would have loved to see a human character similar to Bloodraven, someone who's important and truly on Stormwind and the Alliance's side but who is also tremendously pragmatic and ruthless, and reviled and feared by most for his appearance, methods and personality.
The founder and leader of Stormwind warlocks could have been a perfect opportunity for this.