1. Make the public area and first quest free to play
Zawabi's Refuge has Expert Equipment Repair that you can use if you have enough Free Agents favor. But you can't access it if you unlock it because Zawabi's Refuge is not accessible without owning the Demon Sands adventure pack.
So it would make sense to enable access to that zone for everyone and only disable quests and wilderness entrance in the zone if you don't own the pack.
And then it would be nice to also make Desert Caravan free to play. It is a "first" quest in the pack, you can even enter it from House Phiarlan and it kind of brings you from Stormreach into the desert area.
We didn't get any Free to play quests this year (last one was Tower of Frost), so it might be a nice idea to then make one quest from the old packs Free to play.
Restless Isles have their first quest free to play so it is not something new and unseen.
2. Change quest level of The Chamber of Rahmat to 11
The Chamber of Rahmat is inside a level 11 wilderness zone, it is a part of the Wizard King chain (you get a seal for The Chamber of Raiyum) and it is in every way the same quest like level 11 The Chamber of Kourush. So it makes no sense for it to be level 10.
If needed for balance of quests per level, Desert Caravan is the "first" quest and it could be changed to be level 10.
3. Epic versions of The Chamber of Rahmat and The Chamber of Kourush
These quest are needed to get the seals for The Chamber of Raiyum. They are optional, but it makes no sense for them to not have epic versions if The Chamber of Raiyum has.
Other quests in the pack and wilderness could be made epic too (only Desert caravan could be skipped, but only be made Free to play), but these 2 make most sense because of their relation to The Chamber of Raiyum.
You could then decrease XP in The Chamber of Raiyum since you are adding more XP with these epic quests.
4. Some improvements for the wilderness area (fast travel)
Make some "safe landing spots" in each of the 3 areas (undead, vulkoorim, gnoll) like in Gianthold and add (or change an existing) NPC to take you there once you discover them.
Since the wilderness is really big, you can also add some random encounters there (like in King's Forest). Or just add a few more rare encounters to some isolated spots.
And you can make an epic version of the wilderness, and maybe add random encounters only to that?
5. Revamp old loot
This time, revamp epic items too.
6. Improve the uncut gem trader
The one for Maraud the Mines gems. Make him collect all uncut gems in your inventory at once. The way it currently works is just horrible.
7. New epic/legendary quest
With the wizard Jaefan Druz who absorbs the power from the orb of the efreet as the main culprit?