You asked many questions in the same post...
So, can you clearly state which path is better for (eg.) people who rely on merc and those that don't and based on their weapons or the characteristics of the specialization.
Yes you can, but the possible combinations are too many to count:
-those that choose one ranger path and use mercs
--those that choose one ranger path and use ranger mercs
--those that choose one ranger path and use warrior mercs
--etc.
-those that choose the other ranger path and don't use mercs
-those that choose the other ranger path but really really like bows and using mercs but prefer to fight animals because they are also tanners and need the hides but aren't strong enough to beat more than 3 at a time.....
etc. etc.
So, clearly there is no 'better' path to choose as it depends upon the equipment you use, the types of mercs you use and the enemies you choose to fight and many other parameters. Regardless, you can pick either path to follow, and adapt to it OR pay the 25diamonds to switch to the other one.
As for the skills that you can use in each path, when you reach lvl 14, you will be given a choice, and below each choice, you will see the list of skills and can mouse-over each one to determine the best fit for you.
Even then, you don't have to make your choice right away. You can continue on to play without making the choice, and your unused skill points will accumulate and you can apply them when you are ready (they don't expire).
Here's a tip that I used and suggested to a few of my friends. You are now lvl 11 and have probably already put in enough skill points into the 5 default skill types and each new point you get from now until lvl 15 will probably applied to something that is not needed (eg. I already filled up my critical hit skill bonus so I should put the point into something else....). Don't use them. Save them until you reach lvl 15, then when you pick a path, you won't have the standard 1 point to apply to the new cool skills, you will have 3 or 4 or 5. It might be more useful for you to put those points directly into a weapon specialization rather than poison or herbalist stuff. That's up to you.Hope that helps.