I am confusing region and family names. 
You can just go with Garasai/Turosai for simplicity's sake.
I will still roleplay everything because the Esurks decidedly don't want an openly Aluesiri rule.
1) Family overall would be Garasai
2) "House Quacimisa" is a powerful clan which controls the Quacimisan hills and which has married completely into House Garasai. Every son and daughter of the two houses married into each other, with Turos as their leader.
3) The last paragraph is true. He changed his name to make himself different, keep the title. (having two Baron Garasai's doesn't really work) as well as to pander to the purebloods.
As for the "Frontier Region", it falls under Turos because Erome married his family into all the local houses/lords/clan chiefs that he can get his hands on.

You can just go with Garasai/Turosai for simplicity's sake.
I will still roleplay everything because the Esurks decidedly don't want an openly Aluesiri rule.
1) Family overall would be Garasai
2) "House Quacimisa" is a powerful clan which controls the Quacimisan hills and which has married completely into House Garasai. Every son and daughter of the two houses married into each other, with Turos as their leader.
3) The last paragraph is true. He changed his name to make himself different, keep the title. (having two Baron Garasai's doesn't really work) as well as to pander to the purebloods.
As for the "Frontier Region", it falls under Turos because Erome married his family into all the local houses/lords/clan chiefs that he can get his hands on.