Ah Graliz Sweniz is the language of the Zarack and Izang. (The Dwarves and Burgansies also know this language because of their close proximity to the Zarak/Izang)
Ah Graliz Sweniz means "a god's words" because the Zarack were "given" the language by Natorii and they hold him as their god. I'm not going to post a dictionary, but here is a conversation two characters have in Ah Graliz Sweniz:

Ah Graliz Sweniz
Anaeo: "Gi Kill Nag Staak Skeegin Guy Langtalk Gecaab Ah Keering Dekanders At Ook Gee. Tourk Wak Vurn Ah Ura!"
Jenick: "Tourk Dah Zoura Tae Skee Tae Tak Keering An Think Wahhir. Keemembree Tak Zankeen Stawn Tae Tourk."
Anaeo: "Zankeen! Aff Think Az Quatt Az Kaggor Zankeen - Gi Err Ah Keng!"

English
Anaeo: 'I will not stop speaking my language because a king demands it of me. You were born a man!'
Jenick: 'You do wrong to speak to the king in this manner. Remember the kindness shown to you.'
Anaeo: 'Kindness! If this is what is called kindness I am a Dang!'


To understand Anaeo's insults:
"You were born a man!" --- At that time the Izang were ruled by Kask-Ka, a woman. Kask-Ka had turned the Izang into a matriarchy and males were considered less important. That's why what Anaeo said to the king is insulting, even though the king was born male.
"I am a Dang!" --- A Dang is actually a type of boar in the Lands of Ashta. Dang are vicious animals and are hunted whenever they are spotted. Anaeo is claiming that their hospitality towards her was the same as if she had been a Dang.



Are the words too hard to pronounce?

No, I don't think they are too hard to pronounce, but how are your readers going to know what the characters are saying?

I haven't actually decided if I'm going to include the conversation on Ah Graliz Sweniz. The only reason I really came up with it was... actually no real reason. I was picturing the scene in my head and realized that Anaeo and Jenick were the only two in the room who spoke Ah Graliz Sweniz. No one else could understand Anaeo, but Jenick and he had to turn "interpreter" for the king.
Anaeo knows a little of the king's language, but was insulted when the king asked her not to speak her own tongue.
Thus the outburst

I seconded Airianna's question and opinion. That seems like it would work, and would add depth to your story if you had them translate it. I'm trying to pull off a similar stunt myself.

What I do is I have one or two words written in my language in italics, and then later a translation. See example:

I think Tolkien did something similar in the FotR. When Frodo says the infamous line