Eternal-lands has problems when other programs are running already and use sound. A warning message "open /dev/[sound/]dsp: Device or resource busy" appears, and there's no sound inside the game. Otherwise there are no problems in game. This issue can be circumvented by calling el with the `aoss' wrapper. Maybe there should be an `alsa' USE flag which then wraps the executable?
No, that's a limitation of your sound card and not a general problem. If you need to call it with aoss wrapper, then please do so locally.