Here are some charts that might help you with your opinion of the above; as for me; I will stay on the neutral side and leave things with a statement. You don't go broke making sales that make $ense. So from a risk managment grain marketing plan prospective nothing wrong with making a profitable sale.
As for the other questions; my view is that maybe old crop corn has a little story left in it; but personally I think any additional rally in some of the other grains will be much slower and harder then the rally we seen this past week. Meaning a rally to new highs can be done but I am leaning towards the bearish side; which might prove wrong as the past week I don't think anyone would have wanted to stand in front of the freight train we have seen for wheat, corn, and soybeans.
Here are some charts showing some technical points of interest.