It varies for different websites. But 1.13 is ok. Any CTR is safe as long as its not fraudulent clicks.
1.13% is Ok. It is not too high. Indeed if there is no fraudlent click even if the CTR is high you will not be dumped. It depends where the ads are placed in the page, what kind of format, if keywords are easily readable. Putting the ad at the top of the page or combined with the content, using a larger format, editing title, file name and content may increase the CTR.
As long as they're honest clicks, you don't have anything to worry about. My CTR has never been below xx.x% and I've never had a problem. I had a short spike to xxx% last week on one of my sites (low PV with high clicks) and got concerned. I fired off an email to G and I got back one of their boilerplate letters thanking me for bringing that situation to their attention and saying they will monitor it. Later in the day, CTR dropped back into double digits. I never heard any more from G. But, if your CTR went up because you clicked your ads, all bets are off
it's the against terms yes, but i think it's okay if you say it in general without any hints to your type of traffic, site, keywords, etc. Or not...