I suggest that you play with a gamepad and try out the crossbar hot bar style. I think you'll find it to be really user friendly. I prefer playing with a gamepad, but your preference may be different. However, playing with a gamepad, in my opinion, makes it extremely easy to access multiple hotbars and execute skills extremely fast without having to clutter your screen with numerous hotbars. Again, try out playing with a gamepad and see how you like it. No one can tell you what is going to be best for you.

As far as using your macro buttons on your keyboard...I don't see it as being a problem at all. It really wouldn't be any different than using macros created in game and placed on your hotbar, and as far as any 3rd party tools being against ToS....well, there are A LOT of people out there using parsers, as an example, and while technically that would be against the ToS, SE are aware of the use of parsers and they aren't going around with the banhammer. Also, SE have responded to the use of SweetFX, a 3rd party program that enhances the graphics of the game, and SE have stated that it's ok to use SweetFX and informed anyone who uses SweetFX (or any program like it) that they do so at their own risk.

Also, in regards to using your macro buttons on your keyboard, as far as I am aware it's ok to use them so long as you aren't using them to create scripts for the purpose of botting. I do hope that my response is accurate and has been helpful! Game on!