Cleric domains/spheres. So there will be some spells that sit in a universal domain/sphere that all Clerics get, but the othere domains/spheres that Clerics do/don't get access to are determined by the god that they worship.
I want a Cleric of Pelor and a Cleric of Kord to have more differences than the holy symbol they carry and the domain spells they can cast. They should feel and play differently.
Very much yes.
As for the rest:
Vancian for wizards and clerics (keeping PF style cantrips/orisons), but come up with a spell point system or something like PF's Words of Power for spontaneous casters. Vancian is actually very good at representing full prepared casters; it just sucks at representing much of anything else.
Morale, henchmen, and per round initiative could be done without too much effort, but probably shouldn't be core. Some people really love these, for others, they just slow the game down. Still, they don't actually generally significant changes to the core system itself, and would be natural supplemental material.
Spell interruption would be nice in theory, but figuring out how to do it without completely screwing casters over would be difficult. I would say similar things about most of the other issues raised here. They are nice in theory, but probably not worth the effort needed to get them right, and many of them are definitely not worth the effort of figuring out at the table in the middle of a combat. There's a reason they got left behind; concepts are all well and good, but in actual game application, not all concepts hold up. Some, like the above mentioned, can be tacked on as optional material, but others, like weapon speed, really require integration into the core mechanics in ways that simply add complication that most people won't use or want.
Race/Class restrictions: no, no, no, no, no. I have no problem with, and would even encourage, listing some combinations as rarer, and thus more likely to have social/rp implications that players may not want to deal with, but no outright restrictions. If a dwarf wants to be a wizard, so be it; the backstory and focus should reflect the uniqueness of it, but it should be allowed. For instance, I once created a dwarf wizard that focused on enchanting weapons and battlefield spells/buffs. The character was seen as a bit odd, but useful, and no particular reason to be completely shunned. After all, just because they don't usually focus on arcane magic doesn't mean that dwarves can't benefit from the occasional wizard as much as anybody else can. As a similar example, the normally non-magic using orcs and goblins typically have a shaman/druid/cleric type or two running around somewhere in the background. An army of dwarven wizards or an entire tribe of druidic orcs, on the other hand, would require considerably more backstory to explain.
One of my own I haven't seen (or missed if they have been mentioned):
a return to the one minute round: removes the need for hyper detailed combat round rules, a big source of debate and contention from 3.0 on; would work best if you could keep some form of the standard action, move action (with an established movement rate), free action, etc, in order to keep some uniformity without going into in-depth details
