TV is simple arm linux machine, you could make what ever you want with it. But be sure if that kernel model support operations that you request. At worst case, you might needed to recompile your TV kernel...
I might be wrong but I remember that "BRIDGING" doesn't work between WiFi+Ethernet at linux due protocol differences (Wireless TCP protocol).
There might be there i some work around invented later but when I tried it at old times, DHCP messages passes the bridge but IP packets...
Edit:
I forgot other question. Yes its possible to do such a tool that memorize your channel setting but (personal thought) definitely it will be ugly patch.
2 questions: routing? audio language selection?