Don't have Tomato I use DD-WRT. But the power setting could be higher. It says that heat could have an impact on life. I wouldn't worry about it. Unless you want to go in a add a heat sink and maybe a fan.. Before I flashed the router the default was around 80 mW. That didn't cut it for me so I increased that to 150. UP the wattage to at least 150 mW's. In my settings there is an option which reads, "Sensitivity Range (ACK Timing)" Mine is 40 sense that is about the range I need throughout the house when I do use the laptop.
Are you using encryption? If so, you must make sure the laptop's WIFI settings are correct. Like WPA2 Pre-shared key mixed or maybe your laptop can't use WPA2 or WPA for that matter. Then there's the Algorithm, TKIP+AES, AES, or TKIP?
AP+WDS?? Just AP! Unless you are using two routers, then you would have to configure the WDS accordingly.