Firmware of your WA7210N is up to date? With limited access, how did you make it work again? Connecting directly to the hotel Wi-Fi, the connection is stable?

No... As it is caused by thunderstorm, you may have to buy a new router.

After firmware upgrade, did you reset the router to factory defaults and reconfigue it? Wired connection to WR740N works properly or not? Try channel width 20MHz and secure the Wi-Fi network.

What you need is bandwidth control. However, W8901G has no such a feature.

Your Wi-Fi network is a 11g network and it cannot be detected? Try to change a channel on your router.

Sound like faulty. Did you keep holding the reset button for 15 seconds? Is it still under warranty?