You don't get in trouble for a low CTR or eCPM. The only thing you need to worry about it following the TOS.
eCPM depends on the niche. One of my highest traffic sites is over $75. No amount is too high or small as long as you are within the TOS
Both are normal. While the former is dependent on the kind of niche and source of traffic, the latter is influenced by ad placement and blending and 6% is well within the range. Not to be worried.
Ok, you have a high eCPM. Why are you so concerned? Are you getting high eCPM by some dubious means? If so, stop doing it before Google catches you. If not, don't worry and enjoy