if you search the forum you will see there are loads of moans about it.(dim box). there is a way to turn it off described on the forum somewhere but you have to fiddle with the registry.
You can turn off the dimension pallette. Search for posts on Dimension Pallette.
Here's the thread on how to turn this off
If you're not comfortable in editing the registry one of the posts from Jim Wilkerson has the registry edits that you can pick on to help. One to turn it off & one to turn it back on if you feel the need to.
If I understand your last question correctly, radius dim has always been center pointed as far as I remember. ASME and ISO require this, if I rmember correctly.
If you want a workaround, insert your radius dim. Then insert a leadered annotation note pointing to the same radius. Click on the radius dim while editing your annotation note. It's value will now be stored in the note. After accepting the new value for your note, hide your initial radius dim.