CTR could differ over a period of time. Are you mentioning this for a month or for a particular days. Some days the CTR would be high and some days low. Average it out on a monthly basis. If the CTR mentioned above is for a month period then it seems a bit high though.
There can't be to high CTR, just be sure you play by the rules. Don't ask anyone to click your ads or trick visitors to click them and you will be fine.
where is most of ur traffic coming from ? if SE and its a small niche and the ads are targeted you sure can. I've owned a site before where I had 18% CTR. If you traffic is manly referral, I'd be concerned.
i want to ask google will ban me immediately when they think that i me cheating or will send a warning first
Absolutely it does not. I have sites that regularly get 20%+ CTR and nothing has happened. As long as you are not doing anything you shouldn't be Google is good with it.
For the umpteenth time....If it is attained by legit means, it is fine, if it is attained by violations of TOS/Policies, then it is not okay...simple as that.
I think as long as you dont cheat AS it s safe with high CTR.But aware that s.o try to ruin you adsense account through invaild clicks