If your laptop can detect other Wifi signals but not yours, then this is most likely an issue with your internet provider or modem and not with your laptop. If none can be detected, however, you may need to replace the Wifi card in the device. Refer to this pagefor further information.
First check to make sure there is no food or sticky substance stuck between the sticky keys. If so, pry off the key and clean accordingly. Otherwise, refer to this troubleshooting guide on this laptop in how to disassemble and replace the keyboard or keys.
It sounds like you may have a problem with your fans or heat sinks. Thetroubleshooting page for this device actually has suggestions for this exact problem.