Afair, you can't do it with standard MBeans, but you can do it with XMBeans.
Have a look at the files in server//conf/xmdesc/
It seems to me this should really be a function of the client (i.e. the console in this case).
In full consequence: yes.
Many people use the JMX-console and you can give it a hint by using XMbean-Descirptors.
I think it is a good idea to always have the defaultAttributes and defaultOperations at the same position within the sorting.