Setup 2 is wrong. You cannot use 7210 in this way. You cannot access internet because of the nature of 3-addr WDS.

Setup 1 should be OK. When it "freezed", you mentioned signal is 100% in Antenna Ailgiment, which meas the 7210(bridge mode) is still connected with the 7210(AP mode). When it freeze, you need to check whether you can Ping the 7210(AP mode) and the ADSL router from house_A.

Another thing you can try is to use Client mode at house_A instead of bridge mode if you don't need wireless coverage in house_A. If you require wireless coverage in house_A, you can use WDS repeater mode.

I found a setting in the control panel called ping watchdog, so I set both devices to ping each other every 300 seconds and reboot if they fail. Haven't had an issue since.