The leading char is under your command - even in aggressive mode - if you switch to the DK, you will see "Chuck" is running into peril <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" />
Lockpick and trap skills are worthless skill point wasters => [color:"yellow"]Lockpick is broken, I found trap skills nice to play around with, but only Bosje seems to have explored them thoroughly, he likes spikes IIRC [/color]
About weapons => each to her/his own choice. My DK is 2-hander, I waited until I had this skill, my char archer - only survival skills are pickpocket, detect traps. Only mage skill was Shaman hammer in Act 2 - a very good mage spell to stun/paralyze enemies or in some cases even kill them, lvl 4 was sufficient.
Later on (for end battle) I took the Craftsmanship sharpen weapon and increased my sneak modus.
In the aftergame BF I changed my archer from bow to 2-hand slashing. So far I found better axes and 2-hander swords than other weapons.
When it comes to switching => if I have enough money, I do it. It's fun to experiment.
How far should you build up a skill and to what extent, i.e. damage, accuracy, durability (looks worthless), critical hits, and deathblow? => [color:"yellow"] durability was quite good for my shadow bow, but in all other cases I neglected this and chose the other skills for bow. For my 2-hand DK I maxed out acc, critical hit, deathblow afterwards. [/color]