Yes, the befw11s4 will support 4 "hard-wired" NICs and multiple wireless at the same time. The manual says that it will support up to 253 IP addresses, but I doubt that it will function very well with that many clients connected.
I have had a befw11s4 for about 6 months now, and it is not the best wireless router on the market. It suffers from poor range and poor throughput. It is easy to set up, though, and is a nice combitnation of cable/DSL router with a wireless hub.