You wrote : 1. The ranger can permalag, but the assassin can't. Played well on the ranger's part, the assassin's choice to mark may cost him his life.

Only some rangers can permalag in some niche circumstances. Their ability to permalag can also be countered with preps, the evade skill (which is typically highly developed in an assassin by the time a ranger can effectivly lag) and assassin specific edges. So in short assassins can not be permalaged.

You wrote: 2. The ranger also knows at least one weapon the assassin does not. Makes it likely the ranger will win in a slug fest.

The ranger, being unable to effectivly lag an assassin will not be holding that weapon. In the event he manages to lag the assassin those weapons are easily dodged. Assassins dodge very well already and have edges that let them dodge even better.

You wrote: 3. The assassin can maledict and the ranger, relatively, can't. Increases assassin's chances when the fight draws out.

Exactly.

You wrote: 4. The ranger can use staves and scrolls, and the assassin cannot. DR advantage to the ranger when the fight draws out.

The rangers that permalag can not use scrolls, and assassins can use preps that give the same DR as any scroll. Staves have tremendous lag and cost a weapon/shield slot to use. In the time it takes to brandish again, you have a broken wrist. Rangers have one edge that gives them a little boost with talismans but it's not a game changer that I can see.

You wrote: 5. Both classes dodge extremely well (in the wilds) and both can heal themselves and escape quickly (pathfinding and vanish). So the battles can take some time without the old flee/quaff.

Assassins dodge better in more places than rangers do. Assassins dodge better in the wilds than some rangers do. Especially with some assassin/racial edges. Herbs has a very very long lag and the ranger has to run far to safely use it. By the time he returns the assassin is likely to be in fighting shape, unable to be surprised and ready to put the same amount or more hurt on you since if he managed to mark you, you can't burst damage on him except with a very niche build or call lightning, which not all rangers have. The fight is effectvly over for most ranger assassin match ups when the mark is placed. For me at least.

My own addition to this with regard to perma lag. It requires preps that can be counter prepped and if you are a cloud you have the disadcantage of being highly vuln to a very common attack type.