Thanks for advice, new additions and changes, see if you like them:
Thanks for all the replies. I think Wight is right, I'll change the dwarf to cover his crests with cloth and when asked, he'll give the name adopted by his family. So he will never lie, but will not be telling the whole truth. The crest is only slightly changed from the orginal crest of the lost clan, but only a trained eye with knowledge of his clan can spot it and press for the truth.
I also understand the problem of the 1/2 orc being meant to hate his father. This had been dealt with but I forgot to add it in (the DM asked the same question):
Although raped, his mother did survive the rade by the fathers clan. Orginally the family and village wanted to kill the half breed out of principle. However due to his amazing stregth and abilites, he helped the village out in times of need. He slowly became accepted by the village and treated as an asset and even became considered a blessing after he saved a few of the villages from certain death (something like a house fire or something similar along those lines: this is still to be hashed out). After his mother died from disease, he grew fond of the humans who become fond of him.
He did not only survive the attack by his fathers clan, but was actually taken prisiner. He was then ID'ed and much debate followed. Although he hatged his father and the clan, he felt drawn to them through his orcish blood. He never liked his father but somehow felt at home in the orc lands. The instinct to survive toke over and he learnt to fight in order to live. He always felt out of place and never really fully fitted in. The only real thing he had left was his father (after much of his former family was killed by disease. After his fathers death, he became lost and confused. The only thing that he could think of, was to seek revenge.
Kaag just want somehow to fit in, to call someone friend, like in the days with his mother. But he is always wary due to the time with his father.