i believe you are making this harder then it needs to be.

make sure you are not running your main wow
(wow only resets its resolution at ui load... which is normally at start up)

go to keyclone/ setup/ maximizer ... if you are dual-view, then select the monitor for your main.

create a region
move it to the upper left
resize appropriately
note the size (2500x1600 or whatever)
go to the region-resolution combo box (just under pip)
type the resolution as 2500x1600 (the list is for your convenience and is not trying to be comprehensive)
hit ok

now type the command into the edit field to the right of the 'connect' button
click 'connect'
log in

if it is correct, your mini map should be a circle and not an oval.

if you need further assistance, drop me a PM