The power of attorney to represent the employer should be submitted in the original. Other required attachments to the application for employment of a foreigner may be presented in a copy, provided that the original of these documents is presented to an authorized employee of the state authority conducting the proceedings.
Employment of a Foreigner
Yes, but this is not a sufficient condition, the consul makes the decision.
Employer for whom the foreigner will work.
No, they must have a legalised job. Unless, on the day of the application for a temporary residence and work permit, they had a valid, previously issued work permit, or a temporary residence and work permit, or a declaration on entrusting work to a foreigner for the same employer and the same position.
You have to check the other countries regulations regarding the work of foreigners and posted/delegated workers.
An "invitation to work" is usually the wrong name for a work permit or declaration on entrusting work to a foreigner. Work permit is issued by the Governor and a declaration on entrusting work to a foreigner by the Head of Employment Office. Since January 2018, seasonal work permits have also been issued by the Employment Offices.
Obtaining them is preceded by submitting relevant applications and attachments.