Multiple WNAP210

Let me put it this way - if I were using them hard wired, I would not be using repeating or bridging (we'll discuss bridging in a minute) - the potential problem with a multiple AP configuration is dropped connections if you move between the APs - there is no mechanism in place to ensure a "transparent handover" from one AP to the next as there is in, for example, a cellular telephone system.

You probably could hardwire for PoE and repeat the signal, but, I don't think this will guarantee a transparent handover, and taking the performance hit into consideration, I would try to avoid it.

Back to the bridging - a wireless bridge uses a wireless link to bridge two wired network segments, joining them into a single network - imagine two road networks that stop on opposite banks of a river - just as you could join those road networks and allow the free flow of traffic by building a suspension bridge, you can join two wired networks and allow data traffic to flow using a wireless bridge. I'm sure you will agree it's not applicable to your network installation.

And yes, you do need to configure the access points for the same SSID & encryption key, and use different channels as you have suggested.