Of the brainstorm can see some working, some not.
(5), (6), (7) - totally support those.
(1) Restricting writs to parties.
Do not think this would work, because in other online games then certain content could not be played due to lack of ppl because everyone flock to the golden-path-areas to get max loot. Also where there was group requirement ppl would not take RP build ppl, they would only let other powergamers join.

And if one player got lag-kicked from the game the entire party was booted back to starting area.
So massive bonus for group xp (3) seems good idea as basic incentive for people to join up.
(4b) - Reducing kill xp's impact will pretty much depend on how exactly it is implemented.
Soloing should still be doable, because
a) might have trouble finding party for OOC reason (e.g. unfavorable time zone) and/or
b) might have trouble teaming up due IC reason (character concept).
But at the same time the behavior to stupidly grinding for hours and hours rushing to max lvl -
a behavior best lef to bots not humans - should be impeded.
So if it does not exist already a daily cap to xp gained by kill? Paired with the boost of xp gained via other methods (e.g. RPR bonus, crafting-stuff-xp, and introduction of new non-kill/skill-learing systems of gaining xp (e.g. musical instrument learning))...
(4a) Less writs - Noooooo!
The writ system is a neat list to get idea what is even out there to explore and do.
If anything there should be MORE writs! Especially carthography type writs that take you to non-writ areas to starting point for basic writ-moneys and for bonus you would have to travel further into dungeon. Or just take you to very scenic spots in landscape.
And more tutorial type of writs that introduce you to other aspects of the game like crafting or healing stuff or using/learning spells. They'd not give much xp and gold but maybe consumables like healing kits.
(2) Module redesign - that sure is a long-term goal. Forcing players and their very different character into fewer starting areas would get ppl together. That can be good or create tension. Think the pro outweight the contra. But rather than shifting to Skal for surface char starters (Skal is information overflow in terms of newbie starting, it is packed with buildings...) I'd favor introducing a new starting location for all surfacers all together.
One that is thematically set pre-arrival on Arelith (lvl1!) - at the end of which players get to decided where to jump to next Cordor/Brogendenstein/Skal...
So the already existing content would not need to be changed at all.
Thematically such starting area would need to combine the possibility for characters traveling to Arelith and those being Arelith-born to meet. Another small island seems proper.
Writs be split in two categories:
a) foreign characters
b) Arelith-born characters
So as a foreign character on way to Arelith main you would have to complete e.g. some Asterix style bureaucracy mayhem.
While as Arelith-born character your tasks may be to deliver food rations and waters to some shipwrecked arrivals or maybe even locating them in the first place.
Needless to say this starting area would be cut off from the rest off the servers entirely - being a one way area. No chars higher than at-the moment starting lvl (2?). So no noob-killing PVP drama. Storywise it could be explained because island is controled by some powerful adventurers organisation, or better yet: that one deity that does not allow mucha violence (What's her name again?). So village/camp are would be protected by deity = non-pvp zone, whereas outside areas are just regular adventuring zone.
Also instead of gold and xp the writs would have to give some other other advantage to counterbalance the timegained by just skipping island and grinding as usual. Those things (e.g. unique spells) should not be unobtainable after skipping tutorial island but they should be a pain to get in that method (so not subject to scribescroll n purchase from someone).
...*brainmeltdown*...