Cash Shop Questions

[Derajdefyre]

Hello, I am new to the community and I am considering purchasing the $50 platinum package because it looks like with that much platinum I could afford all of the content expansions. Before I do this, I have some questions I would really appreciate if the community could answer for me.

1) Is the best gear in the game from the cash shop or is it dropped in the later dungeons?
2) Does it matter who gets the killing blow on the enemy or who opens a treasure chest, or is everything always shared equally?
3) All the armor I have tried on looks exactly the same except for color. Will this always be true?
4) Is my assumption correct that if I buy $50 worth of platinum I can buy all of the extra PvE and PvP content with plenty to spare?
5) I have seen posts about dual wielding. Is there such a thing or are they talking about using a two handed weapon?

Thank you in advance for taking the time to read and respond to my questions!