Check these, please!

[Anonymous]

Hi,
Please check these sentences and correct them.
1. Get down. & Get yourself down. [If both are correct, is there any difference in meaning?]
2. Most translators get specialist training, but I don't know what (the) specialist qualification is called (for).
3. John is (sitting) at the piano, playing beautifully.
4. He was seen/witnessed [to steal, stealing] a wallet in the tube/train.
5. The documentary is going (to be) on (the) air tonight at 10 o'clock.
6. He has two daughters, (who are) both very athletic, just like their mother. It runs in the family.
7. His step-mother raised him since he was seven, but when he was twenty, he looked for his real mother and has lived with her up to now. Blood is thicker than water, you know.
Thanks a million.
Ann

[Anonymous]

1. Get down. & Get yourself down. [If both are correct, is there any difference in meaning?]
Get yourself down does not sound natural at all. I would say 'get down' is better but it sounds like an order. if that's what you're looking for then it's fine.

2. Most translators get specialist training, but I don't know what the specialist qualification is called (correct)

3. John is sitting at the piano, playing beautifully. (This is fine or you could just say, "John is playing the piano beautifully."

4. He was seen stealing a wallet in the tube/train. (correct)

5. The documentary is going to be on air tonight at 10 o'clock. (correct)

6. He has two daughters, who/that are both very athletic, just like their mother. It runs in the family. (either option sounds natural)

7. His step-mother raised him since he was seven, but when he was twenty, he looked for his real mother and has lived with her up to now. Blood is thicker than water, you know. (correct)