AXI AHB APB quick reference cheat sheet

Hi, I have tried to find a quick reference for AXI, AHB & APB to no avail, and after having to flit between the various documents and tables, I eventually created my own. So not sure of the legal...
AMBA APB

1)what is the difference between with wait state and with no wait state(read/write)?what are the advantages of both in APB?
AMBA APB

1) the APB uses massive memory-I/O accesses.what is that massive memory-I/O accesses?
Why does AHB or APB support only 16 slave devices?

I would like to know why only 16 slave device select lines are present in the AHB and APB bus architectures.
amba ahb

hi, Is HREADY is used by the slave to notify the master that it is ready to receive or to indicate transfer is completed?? thanks in advance