1. The Xeroms might be considered different than summons. For summons, our definition is meant for beings, creatures, or spirits that can appear repeatedly and as a weapon equivalent is more like the character's main sword. It's not an object that would be discarded carelessly and is more "permanent" in a sense. Given the nature of Xeroms, I might equate it more like a magic spell. For example, a fireball. You can repeatedly cast it in finitum. So although Xeroms are "sentient" in a way, these can actually be attacked and defeated and aren't meant to have long life spans. So rather than a "summon" they're just an attack ability. (Which means that any other character who can summon "monsters," like the Noise from The World Ends With You and the Heartless from Kingdom Hearts would also be able to.)

2. That is doable!

3. Hmmm good question. Any metal furniture would probably be able to handle heavier weights, but the furniture is more or less standard and similar to what you find in real life.