Id say Creation 3 could be add +1 population, Creation 2 could create a building of +3 health
I like the Fall Further "accelerate", the haste for non-living units. But maybe more appropriate for Force 2 ... So Khazad are still slow and lumbering, or Force 1 and only available to Khazad to help avoid this same tendency. (well and grigori too... I guess

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I think itd be cool for Force 3 to be Levitate, to either allow flying or move on impassable. maybe could be designed to be limited in some way if it turns into OP. I do luv mah elderscrolls.
Dimension2 could be another form of caster enhancement/protection, and the opposite of stoneskin. AKA +50%withdrawal rate. call it phasing. Although I would kinda like Dimension 2 to summon some creature that either can teleport or move directly through things. Maybe a creature similar to pitbeast/ einherjar, only it ignores terrain defenses? instead of lasting longer if surviving?
Edit: as to implementing the 2 linked portals, I would suggest it being a 2-part spell, point A and point B. perhaps you need either the archmage at point B to keep it open, or some magic user at either point. Or.... to have a spell acessible after you build pointB, called Close Portal. I certainly think such portals would need maintanence, but meh.
To streamline, perhaps have separate closing spells "close A" and "close B" a great way for insta reinforcements by keeping A inside a highproduction city. Then new units could just use "enter portal" to arrive at the front lines. Muahahahaha
Second Edit: Okay, upon further thought, I REALLY feel the need for an entire stack to be able to either pass over mountains(impassable) or cross over ocean(flying) by the time SoW comes around. Its nice to use boats, but I really dont think you should HAVE to use boats if you can mold the ether to your will. In some ways I like the extra strategy of reaching a hard-to-get empire, but in the end ... when youve already won the game... Daddy needs to steamroll EVERY Map-type.
I think a Force3 levitate could easily accomplish this.
Third Edit: As of now, I would say either Fire II or Shadow II has become a necessity for taking cities (well not necessarily, but some could argue ... especially in MP) I think that having an "accelerate" Force I, for either non-living or just catapults even or just cats and golems, to get the extra move point. I know possibly making them slow is for balance, but a properly upgraded ALL living stack can have move 3, while golems and cats are stuck at move 1. Even demons and undead can get to move 2 without much effort.
I would honestly see it fair to just be applicable to catapults, as Golems seem to be balanced properly if not OP (blasting workshop :cough

but I really like how golemsare currently anyways.
That being said, I seriously think that catapults are underpowered and generally never used ... which maybe against lore to an extent, idk. Well, with force1 you could have move-2 cats! while not fast enough to help my horsemen on the field, they can certainly have a better time catching up to help with the siege.