My thoughts on the items presented in the UA / Wayfinder's Guide to Eberron.
1) The armblade would function better as a racial ability of the Warforged Juggernaut subrace, similar to the Warforged Envoy's Integrated Tool ability.
2) If the armblade is an item, it personally doesn't make sense to me why it requires attunement. It isn't a magic item. Even +1 - +3 magic weapons do not require attunement, and this doesn't even overcome magic resistance to bludgeoning/piercing/slashing damage. Currently, an armblade could be replicated by any warforged or non-warforged by attaching a bungee to your weapon and your wrist. Ideally, an armblade would function similar to the wand sheath, allowing the warforged to switch the weapon being used by the armblade (maybe instead call is a Warforged Weapon Sheath). Also, it would allow an Object Interaction to sheath it or call it up. I personally dislike mechanics that require one to use a bonus action to call forth their weapon just because it is a bit more flavorful (see Tome of the Blade or the Eldritch Knight's Bonded Weapon for examples).
However, since the Wand Sheath not only holds a wand, but frees your hand while using it, I can see why the wand sheath would require attunement.
3) I like the Orb of Shielding. However, I would also add one's proficiency bonus to it. This maintains a small amount of damage reduction against an energy type, but allows it to continue to have use at higher levels. Given that spellcasters are less likely to use reactions for things like Attacks of Opportunity (outside of those with the Warcaster feat), I think this makes sense.
4) I like the idea of two-handed focuses for spellcasters. However, I do not like that it increases distance. Personally, outside of very rare niche situations, distance in my games for attacks rarely go beyond the 60ft - 80ft range. Well within the range of most ranged cantrips. Instead, I would increase the damage die by one step. I mean, two-handed weapons deal more damage than one handed weapons, so why not the same for two-handed focuses. Yes, this is an average of +1 damage per die, and some may not like the idea of a caster having access to a d12 eldritch blast. One could instead limit this to melee-based cantrips to combat this problem. But for me, this also makes sense since in my games I use bucklers. These can be used by anyone, even without shield proficiency, and add a +1 to AC. As a result, at least in my games, this would become a meaningful choice. Of course YMMV since every table is different.
