I would suggest this change.

Can I create an arc at a specified length?

There is no specific length parameter with arcs to do this, however you can use the data entry window with a little math relating the starting point,length, and radius.
The angle of an arc is related to the length by the below equation:

Total Angle = Length / (( 2 * Radius*PI)/360)

To apply this within the CAD application, first create an arc with the correct start point and radius using the Three Point Arc tool. After the arc has been constructed, select the arc and tab over to the Total Angle field in the data entry window. Type in the following for a desired length of 15 and radius of 5 in the Total Angle field and hit carriage return.

15.0 / (( 2 * 5 * PI)/360.0)

To confirm the arc is at the desired length, select the arc and the Verify : Length command from the Menu Bar.

Simplify the above to: rtod(l/r).

Using the above example. Enter into the Total Length field: rtod(15/5).

Hi Tim
Probably not worth it but
There have been a few plan drafting questions on how to dimension outside or away from the floor plan.
The dimension settings have extension gap, extension over ect. But where they get confused is that they want to click on the line and pull or place the dimension off to the side without the dimension lines going through the floor plan. And they don't want to tweak every dimension.

Trying to explain you can pick a point and using the logicursor place the dimension outside the floor plan seems like a hard concept to get across to them.

I have attached a plan to explain what I am trying to explain.

Also has any work been done on the hatching tool in the new releases. I'm still on Viacad 10 but it is always a bit of a lottery on if its going to work.
Thanks
Mark