You can switch ether2-ether5 and ether6-ether9, bridge together both master-ports and wireless interface.
Will doing this result in using the CPU or will they all be at switch speed?
I currently sacrifice two ports (one on each switch) to get the full speed. Is the way you posted better?
The two switch chips are wired to different physical sets of ports. You can only switch (at wire speed) ports that are on the same switch chip. You should try and lay out your devices with this in mind, if at all possible. In my case, I need to bridge/switch ports 2 through 7 together, but two of those ports have only a single device each that do relatively little, so putting them on the wrong side of a bridge is not a big deal.
So in my case, the master-port of Ethernet's 3,4 and 5 are set to ethernet 2. Ethernet 2, 6, 7 are connected to a bridge, and the bridge interface gets an IP configuration for the inside LAN. Ethernet 9 has a master-port of 8 and 8 is bridged to an L2TP bridge link off-site.