Why not the singular, "another alternative"?
When does "ska" mean "should" compared to it meaning "will"?
I'm also confused between "shall" and "will" when we use ska!
You have to enable skall=ska
Vi skall leta efter andra alternativ. is an accepted answer.
Does skall have the same slight stronger meaning that shall has?
No, it is not!
"Other alternatives" is redundant English.