Adding the DME early can effect hop utilisation from memory. I've done a strong Belgian beer before and that had me putting in some dextrose 2-3 days after pitching the yeast.
I'm sure others will have some more specific information in regards to your style of beer.
- Cheers
I'd be careful with zest. I've used it in the past and it came out really tart. It's taken nearly a month and still needs more time conditioning. I only ended up using 1 orange worth of zest for a 23L batch.