Regarding the lenght.
If you work with WF5, have you tried Info>Cabling.. ?
This will give a repport of every lenght which can easy be share with notepad.
However to measure only segments or small portion...you may use the Analysis > Measure > Cable. It will eneable you to take mesaurement by picking green dots to green dots.
Regarding the overlap
It seems that Brian Martin answers a similiar question here : http://communities.ptc.com/message/223356#223356
If ever you really want "physical interaction" I think CreoDirect offers something interesting...but its a different software than Creo Parametric (ProE) and I haven't tried it yet.
Have a nice day