As a maker of both chisel ground and conventionally ground knives, I'd like to make a few comments. this question comes to me frequently, and I do plan to tackle it in more detail on my website at a point in the future.
There are chisel grinds with and without secondary bevels. This has been said here. I produce both, but, primarily the "zero thickness edge" one, mainly because I make tactical knives designed to cut clothing and flesh.
There is no easier knife to grind than a totally straight edge with a secondary bevel. which may be why you see so many commercial folders with this type of edge geometry and grind. With only one side ground, grind line symmetry doesn't matter, and holding a constant thickness edge doesn't really matter that much, either-you can compensate for varying edge thickness when you put on the edge bevel. Also, you can use a workrest set at the desired angle, and just go nuts. The benefits of the chisel grind that come from less friction during the cut are lost to a greater degree as the thickness of the secondary bevel increase
I havn't seen many traditional Japanese knives with perfectly straight edges or points-they understand that the curved edge slashes better. All my chisel ground blades have curved edges-some more, some less.
When grinding my blades, freehand, of course, I have to get the entire edge at the same thickness at exactly the same time, or the edge would be wavy (grinding too far in one spot), or, there would be a flat spot where the edge wasn't thin enough. This is not a simple thing to do, although the challenges involved in doing it are different than those faced in grinding a double grind.
As for the edge being off center, if the knife is canted slightly in the hand, the edge can be oriented in use just like a conventionally ground knife.
When cutting different materials, the chisel grind does behave differently at first (difficult to cut straight, wanders), until your hand develops the ability to control it.
On high speed, high impact cuts, like Martial artists make, the chisel grind really rocks. Don't really know why, but, it does.
And, there is the matter of personal preference, which can't be discounted.
One last thing-the bevel angle has to be carefully matched to the steel and the heat treat, as well as the intended use of the knife and the stock thickness of the blade.
Hope this helped some.
RJ Martin