My suggestion is .................................................. ....
1) Camouflage spell
Now acts like Displacement spell as long as ranger has attained the Hide in Plain Sight feat. I really want to look like the Predator character that even detected its camouflage device makes it difficult to hit.
2) Pass Without Trace spell
As long as ranger is invisible (think invisibility pot), the ranger cannot be heard. Therefore can pass undetected. OR. Would allow a ranger FIRST STRIKE opportunity by getting close enough (melee range) undetected. Ok not so useful but its part of a theme.
Ture Seiing mobs ignore these effects of course.
Just a tweak to make some of these spells more useful and add a layer of survivability through ranger specific spells to the ranger. Sure these suggestions have very little to do with the PnP rules but the DDO gave has already shifted substantially from that. So why not tweak otherwise less useful spells.