The Hidden Forest

Can I only begin in Stonebrunt once I ally with one or the other factions?
I have roamed the zone trying to figure out what to do next and only found the Kejek and the coastal area with named NPCs.

Once you pick a side they will give you quests. Also there are some quest npcs on the dock area near the boat.

there are 3 quest hubs in SB:

-the docks with the big ship
-the Kejek Village
-the Snowfang camp at far end of the coast

you can do quests at the docks right away
But to do Kejek or Snowfang quests you will have to choose who you are allying yourself with.
To do that, you will need to talk to either Kejek or Snowfang emissaries - they both found not far from the Warrens zone line

some details here
viewtopic.php?f=59&t=4108

Thanks for that info.
Is there a way in which I can check what weapons and such I can craft for the different alliances/factions?

Are the elder Runes usable or is that something that did not make it due to the content being cut short?

on Elder runes - talk to Master Weaponsmith ion Paineel - he will tell you what to do with them, to enchant crafted weapons from Warrens

on crafted weapons for SB: you can look up stats on Alaclone

Kejek:

Etched Wood Bokken (49549)
Etched Wood Maulet (49547)
Etched Iron Dadao (49513)
Etched Iron Katana (49511)
Etched Iron Katar (49501)
Etched Iron Naginata (49515)
Etched Iron Qiang (49505)
Etched Iron Tanto (49503)
Etched Iron Wakizashi (49509)
Etched Iron Yari (49507)

Snowfang:

Etched Wood Elder Staff (49550)
Etched Wood Shtok (49536)
Etched Wood Warclub (49548)
Etched Iron Battle Fork (49508)
Etched Iron Gleffa (49516)
Etched Iron Juggar (49514)
Etched Iron Khar (49504)
Etched Iron Shrathan (49512)
Etched Iron Ulak (49502)
Etched Iron Yatagan (49510)

thanks thanks...
out of curiousity I killed muglwump but quest did not update.
I did kill him with the enchanted bracer with the hammer of wrath pet.
would that make a difference if I did not get the kill but pet did?

really enjoying the alt p content.

figured it out. it indeed made a difference when I did not use my pet.

thanks for making this content. I hope some time in the future if possible you return and complete it chaos

the pet probably got a killing blow before

small correction to my list above - it should be Etched Steel instead of Etched Iron for the crafted weapons

after crafted they can be upgraded to Spirit Infused weapons.
But I let you figure that out on your own