To start your nikah is valid and correct.
To your three points:
- The girl lied about her age and I found out her actual age after nikah when I started speaking to the girl. Her age is a concern for me as she is older than the age mark I would have considered for marriage.
This might be lie, but for the validity of the nikah it is irrelevant, but indeed it can be a reason for divorce, if it is that important to you. But if you didn't tell and make this clear... to me it would look like an excuse. I myself didn't want to marry a girl whom would have such an age difference as I actually have with my wife, but at least what counts in marriage is that spouses can get along with each other. Therefore I would never accept an arranged marriage as I need to get to know the girl myself first.
- It was not disclosed to me that she had a nikah in the past which ended in divorce before ruksati.
This doesn't invalidate a marriage at all. Divorce is a halal separation, even if it was after consummation of marriage if it was before than it is even better. Do you know the reasons of this divorce?
Again this shows your mistakes of not trying to get to know the girl you were about to marry. A girl is not forced to disclose about her past unless the future husband made what ever she has hidden as a condition for marriage. Like if he made virginity a condition and she lied about it and he found it he could divorce her and ask his mahr back.
- The girl’s attitude is very bad- I noted this even before I found out about her previous marriage. The foundation of the marriage is based on lies and I am not convinced whether I can trust my wife.
This is no reason to invalidate a marriage, but again shows that you didn't take your time to get to know the person you were about to marry. It might be a reason for talaq however.
Note that for nikah to be valid you need: the acceptance of the guardian of the girl, two witnesses, you need to name a mahr and of course the acceptance of the girl (assuming you are accepting to marry her) these things might be written down in a form (but it is not considred as mandatory) anything else has no basis in shari'ah.