Modifie and new FFMPEG commands in a working project

Our project is based on PHP/mySQL. There are two parts admin and users clip to combine. The following tasks has to be modified or to make new. 1. The admin should set a time limit for the users uploadable episodes. After the user is uploading his episode he should select the desired part of his clip (like a upload of a lang video in WhatsApp) 2. The user should be able to upload multiple images/pic with a multi selection. The images should be displayed for 2 seconds in the clip. 3. In addition to the upload of background sounds make some electable with a drop-down. 4. When uploaded movie do not have audio add a standard background sound and display a massage. 5. Option to switch for the admin to overly the users sound with his background sound. 6. In addition to the main clip we have pre- and suffix clips. The sound of this has to be separate and out of the main video sound. 7. Make the clip from the user into the main video by fade in and finish the clip of the user by fade out. 8. Merge two video clips into one, placing them next to each other. If there is a cutting point in this part overlay the twin part. 9. There is a second video created in the background. This has to be done without the pre and suffix Are you able to do this job and apply me if you're available. Thx,