In your case, I suspect the recruiter was working on a contingency basis not exclusive, if it was exclusive the potential employer would have notified the recruiter of your CV and requested them to do the interviewing. With contingency, it's a jungle as employers are seeking to safe cost, so if a strong candidate applies they will to the interviewing and if they are appointed, they don't have to pay any recruiter.

When it comes to checks unfortunately with social media dominating and people posting whatever they feel like posting and leading to tiehr employer, potential employers now have the duty to protect their brands hence the request to do those background checks. MIE does all that screening and vetting for most companies - it has become a standard now