Can foreigners work in Japan?
Yes. Residence permission depends on the type of industry.
Is there a time limit on residence permission?
The term can be renewed like a driver's license. As long as there are no particular problems, it can be renewed.
What level is their Japanese?
Interpreters (College of Foreign Languages) are proficient, though it is difficult to demand Japanese skills in engineers.
However, their Japanese will improve on the job.
How long do they want to work in Japan?
The largest number want to work 5-10 years. About 30% want to work for more than 10 years.