HELP!!!bluefruit nrf51 as HID with 20 buttons+rotarys

hi all:

i am developing a personal DIY project, a buttonbox with 16 buttons and 6 rotary encoders.

in 1st instance , i was working with arduino leonardo , due HID gamepad capabilities, but i need to upgrade to BL, then i have bought a bluefruit feather nrf51,but when i am searching over internet , i only find Keybpoard HID, with restriction to 1 pin - 1 button.

my Knowledge is basic, so i am lost and start frustrating.

any idea?

can i adapt my previous sketck (using joystick library for 32u4) to send data over BL?
can i use rotarys with HIDkeyboard ?
can i use button matrix on HIDkeyboard?

thanks a lot!!