Halal and Haram in Recruitment industry

I am working as a recruiter. My main duties are basically cold calling clients to see if anyone is currently hiring or will soon hire and find candidates to according to the clients' needs. Recruiters get commission of a certain percentage of a years salary from the client. I always make sure the job itself that I am recruiting for is halal. Oftentimes, recruiters get in touch with candidates who are currently employed and give them lucrative incentive of their clients' so the candidate who's employed changes job. This might really be beneficial for the candidate in terms of their career and salary. 1) Is this act permissible? 2) Does this fall under the hadith of selling an item at a lower price after someone else has made an agreement already? (inducing employees during the period of the contract to leave their jobs and move to another one just in order to get a commission from them) 3) Most importantly, what if the candidate him/herself is looking to change to a new job by posting their CV online waiting for recruiters to contact them with the opportunity of a new job. (Passively looking candidates) 4) The candidate has not signed a contract with the current company on how long to work and can leave the company anytime with a month notice? 5) Similar to Q4. The candidate has signed the contract of working for a certain number of months and has met the requirement and can now leave with a month notice. Please help me answer these 5 questions. Really appreciate it. May ALLAH Ta'ala bless you all. Jazakallah Khair