Scouts got shafted when staves were removed from their skillset and crossbows were added. I'm not saying that scouts are not great in PK because they have some really great skills for it and preperation doesn't take that long either.
I do feel, however that in comparison to the other adventurer classes they are the weakest. The only thing a scout has going for him in a non-camo environment is its pet. In a wilderness environment it has ambush. Both are excellent skills but lets face it a character shouldn't feel that limited. Look at rogues: Why can they utilize scrolls yet scouts are unable to use staves? Personally I feel bards are pretty well balanced as far as the game goes.
I think scouts need to be looked at, but not necessarily have skills like trip added; they have pets for that as was stated. The applying herb affects to weapons is a great idea that has been floating around for a long time. I wish it were looked at as a viable addition. I think the most important thing is that the skills they currently have are looked at a bit more carefully.
For instance take fletch as an example. Fletch allows the scout to make arrows and based on its level the quality goes up. That's a great skill and allows the scout to be more independent. But if a scout can find the materials to make arrows doesn't it make sense that it could find the same materials to make a spear. Change the name of the skill to craft and there you go. Limit what weapons you can craft and the quality by level or status and you have an improved scout skill.
Another idea might be to tweak tame but a certain amount of coding will be involved. The idea would be to add a new flag into the game that is tame specific so instead of the animal you tame being charmed it is flagged as tamed; this would not be detectible through detect magic anymore. This new flag would be added in order to allow the tame skill to be used in battle against store-bought/"charmed" pets to stop them from attacking for x-number of rounds or until ordered to attack by their owner again. It would be increasingly harder depending on how many things the scout is fighting.
Herbalism could be changed to allow a scout to not only find, but "remember/identify" an herbs effects based on level and even add the ability to save against the adverse effects. The list really goes on about what skills could just be improved in order to make scouts better rather than adding new ones. As it is now they are a viable class that could use a small boost and they already have a good skillset to build on so they probably won't be changed anytime soon, but here's to hoping.