The way I see it, most of the elite pikemen of each other faction has something other then the porcupine formation that made them unique (Tower Guard armour formation, Cirith Ungol orcs being strong vs swordsmen and no cp, Rohan Westfold Pikes having the abilitys of the captain, and Erkenbrands summon Having a spear throw if I remember correctly, I feel like i'm missing one so feel free to tell me if I am) The 2 factions that can only build 1 pikemen unit and/or have no elite pikemen (dwarves and Isengard) still have something unique that improves them (Uruk pikes can combine with Shield uruks, making them much more versatile, and Dwarves have are unique depending on what subfaction you choose. I can't remember the eredluin ability, but Erebor has the building weakener and Iron hills have the speed up ability. And if i remember correctly, dale and laketown pikes have the standard porupine formation) Again, tell me if any of this information is wrong.
I think that palace guards are missing a formation or unique ability that make them compareable to the other elite pikes. Because while the porcupine formation has its uses, I think the palace guards should get something new. Preferably something that increases their armor. I think that may be enough to make them stronger, without the need of a armour upgrade, but if its not, maybe slightly increasing their base armour values would be smart.
As for the lorien Pikeguard, i think their speed up ability is enough, but if they change the palace guards ability, i think giving them the porcupine formation would be good.
I don't have time to comment on your other points Elite KryPtik, but I will post when I do.