I would just like to add some comments on the features you descrive.
Avoiding encounters should sometimes be a smart thing to do. Therefore I'm currently trying out the following changes:
I think that avoiding combats is something that comes naturally with difficulty. Players do tend to avoid combats which they think that are too dangerous.
* Removed experience and levels. You pick all your traits and skills when creating the character (this also provides more opportunity for the player to experiment with different character types)
Although this feature presents itself quite flexible, it is prone to bring problems later on during gaming, when you realize that the skills and traits you've chosen were not the best combination or that those some skills and traits were not what you were expecting them to be. It happened to me when I used to Play Fallout 2 in which In some occasions I was forced start it all over with a new character. I still prefer creating a fresh character and letting the player train it at will throughout the whole gaming without restrictions whatsoever, while making sure that the character won't ascent in every field.
* Some monsters will be much tougher - more incentive to avoid combat.
Yeah. That makes sense.
* Generally fewer monsters spawned. More free space = more opportunity to find alternative routes and avoid encounters.
This heavily depends on your game play mechanics and general world setting mechanics. If your game is all about hack&slash that won't work. If your game has a deadly combat system it can work, if you make sure that the game won't have extended moments of game play without any action, otherwise you risk yourself providing the player with some really tedious moments. Then you have to specify how easily it is to avoid confrontations because if it is too easy to avoid battles than it becomes to easy not to die.
* Sneaking is affected by range - a monster at the edge of your field of view will often fail to spot you, even if you don't pick the sneaking skill. More opportunity to avoid encounters.
That's a must have
* Introducing "Wounds" which require a resource to heal - causing combat to have a long-term cost. More incentive to avoid it.
If you have a deadly and realistic combat system implemented, I'm pretty sure damage will be applied over body parts and compromise those parts, which in the end will be the same as the "wounds" you refer. What can really make you think twice about engaging combats is how difficulty healing can be. This can be done trough having few healing resources yes or needing long periods of time to fully recover.