So the basis for my gripe with the gunslinger Throwing Knife is that it does not inflict elemental damage unless you take the perk for it. Other classes have their melee elemental damage from the get go. So why not give the base elemental effect for throwing knife and just let the perk add the dot. Then using the knife would be useful against solar shields mobs.
now for the perk rant:
The first perk (Circle of Life) for throwing knife is totally useless for its active part. Only thing good about it is that it increases armor. The increase in time to use the golden gun is not something that you would use unless you have a habit of using it prematurely. In Pvp if you have golden gun you dont take chances with the enemy and take your aim off from the target for a knife throw that will most likely not kill. In pve the only enemies that die consistently to TK are equal lvl red shanks, dregs, acolytes, thralls and psions. Everything else will most likely survive the hit. Also when using golden gun in Pve i think most people will use the keyhole perk unless they are using celestial nighthawk thus making the need to remove the obstructing enemy a trivial thing. Also the enemy AI with dregs, acolytes psions will hide behind cover thus reducing the amount of possible targets to get the use out from the perk.
Incendiary blade is useful due to the elemental damage that it gives to the blade. That elemental damage is good for shielded shanks and centurions and dot is good in pvp for keeping the pressure on someone. I think that this perk should have been the base effect with a slight reduction in damage of the dot from the beginning.
Knife Juggler is good perk with the precision hits since most red cannon fodder enemies die from that hit(equal lvl enemies) and you have all the time in the world to get the effect. In pvp its good if you have +1 situation and you know you got hits in with your gun and you have to conserve ammo.
Now for the suggestion part of the post
i would suggest that the TK skill activation would be a continous press of the button rather than the both melee attack and TK share the same button press. With continuous press of the button lets say for a 1sec you would throw the knife and with a quick press you would use the basic melee strike. That would reduce the amount of wasted TKs. The player would have a proper decision for the use of the skill since the charge is used whether the knife hits target or misses. Other classes will not lose their melee charge if they dont connect with it thus its not a problem for them.
For the base effect a good change would be add the elemental damage to the TK if the dot sounds too big of a buff for base effect.
Circle of life i would scrap altogether and make a new perk that would alter the range, arc and speed of TK. in my opinion a good perk would be a throwing dart that would fly bit faster and in a straighter arc but would have a maximum range that it can travel that would be shorter than the normal throw. the range could be justified by infusing the dart with solar energy would burn the dart that has less material on the blade than the knife of the basic throw. This would make the knife useful for dispatching goblins and hobgoblins since their head is not the precision hit point.
I would keep the incendiary blade as it is unless the dot effect would be added to the base effect. then something could be added.
Knife juggler is fine in my opinion nothing fundamentally wrong about that one.
So thats something i have been thinking about that would make the Throwing Knife a more varied skill.