Need help here i don't know if this is allowed playing 2x lilandra and if a friendly character that has both keywords for that trait would both traits go off on the character giving him +2 atk and +2 dmg

First, always helps to quote the text/description of the Power/Trait you need help with:

DEFEND ME, SHI'AR WARRIORS!: Other friendly characters with the Shi'ar keyword and within 8 squares modify their attack values +1. Other friendly characters with the Imperial Guard keyword and within 8 squares modify their damage values +1.

Second, if you were playing in a game that would allow a player to play two copies of her then you would get the +2 if the requirements were met.

Most game effects like this that wouldn't be stackable, thus not allowing the +2, would usually end with the phrase "...unless already modified by this power." That line is not included in the text of the ability, therefore you are good to go.

That being said, I'm not an Orange so don't take my word for it, but that's how I'd rule it. Always consult your local judge.

Hope that helps.

If you run 2 Lilandra, any other Shi'ar/Imperial Guard member within 8 of both will get +2.