If I create a song using Mixcraft's loops, can I sell it or distribute it without having to pay Acoustica?
Providing that you legally own a Mixcraft license, you may redistribute new works of art, podcasts or other sounds created using Mixcraft's loops royalty-free for any and all commercial and non-commercial uses, but you cannot redistribute the individual loops by themselves in any format, medium or recording.
Note for Mixcraft 8 users - sounds downloaded from the Freesound.org archive have various licences. Some sounds ask that you attribute the source of the sound. Some sounds are for noncommercial use only. The rules for any particular sound are linked in the Licence column.