How could working for Burldries impact Karg? Karg is expecting his work with Burldries to provide him with a good chunk of coin but other opportunities could give him a reason to stick around.
A show of how strong Burldries and his forces are, along with a guarentee to support Karg in his attack on the bandits could go a long way in securing his loyalty. Likewise, offers to make Karg stronger through magic items or blessings, could help keep Karg around. (Revenge is always nice)
Conversely, actively being dishonest to Karg or endangering him/those he likes needlessly would damage any future relationships.

The only solid parts I have for Elsma are:

• She was taken from her home by Gunzar's Tribe
• She is Karg's Birth-Mother
• She willingly used Karg as bait so she could escape, suggesting she doesn't care for him (Although Karg himself does not know this)

Some other aspects about Elsma that could come into play are:

• Who was Elsma? Was she just a random girl who was taken from her village when it got attacked? Perhaps she was a noble's daughter or someone influencial, giving Karg some legitimacy in the world.
• Where is Elsma now? Is she still alive? Has she managed to escape in the time since Karg left? Or maybe with Karg gone, she took Gunzar's offer to become part of the tribe.

Was it really a miracle that lead to the stranger saving Karg? Or perhaps the beginning of certain wheels being set in motion for the future. Need to make a bit more information about the stranger.