Hi, I work in the media industry. I film and edit, and I also run conferences, hence am familiar with your requirements.
Would like to seek some clarifications.
1. You have an 11.5min video?
2. You want it trimmed to approx 3 minutes?
3. You're hiring a video editor, is that right?
4. You have slide pages you'll like to include into the 11.5minute video to bridge where the trimmings are?
Do tell me, thanks!