Hello I am building a workbee cnc. I use a 800W spindle with an ER11 chuck.
So I choose to use 6mm bits.

I will cut aluminium, and hard woods (mainly bubinga and some ebony).

My bubinga pieces are around 45mm in thickness, contouring them is what leave me puzzled !
Do I need to buy a bit with at least 45mm cutting area ? Or can I use smaller bits with multiple passes?
Will the non-cutting area rub against the wood and create friction ?

Also I cut a lot of metal (mainly aluminium and stainless steel of 2mm),
can I just buy a 4flutes HRC60 bit and use it on bubinga wood ?

Because I read that wood bits use a different cutting ?radius/shapness? is it true.
I wanted to do everything with these bits : https://www.aliexpress.com/item/33042760122.html

Thank you for your help.
I watched a lot of videos but none explain these things.