Have u checked the automatic label placement???? If not then try it out. I think it will solve your problem...
Go to Modify---> Label ---> label placement
select all the Labels
then give the placement definition
All the labels will be automatically placed as per your given definition..
I hate when they go out side the veiw!!!
Run it once and them go out the, you should be able to see the leaders.
The open the auto placement box again and remove all the lable then select i think its id labels ( NOT In pdsm to check) and tou ch/pick the leader lines of the ones out view. Increase you maragen value and re-run . Now you will have two layers and will havet to tweak the hell of it but at less all your labels where you can get to them easy.