If I have a 2 might unit on the Amateur Recital battlefield, and my opponent has placed a Bomb gear token on the same battlefield, what happens when my unit holds? Does the Bomb gear token trigger happen first to deal damage or would Amateur Recital allow me to move the unit back to my base because of holding?

Radiance rules aren't published yet. This uses the printed card and current rules only, and it isn't a ruling on the new mechanics.

The Bomb's Deploy trigger resolves first — but the 2 damage it causes doesn't trash your unit until after the chain empties, so Amateur Recital does still let you move the unit, and the unit dies anyway.

Here's the order. In your Beginning Phase both triggers fire at once: your "when you hold here" ability and the Bomb's Deploy ("when an opponent holds here, kill this"). As turn player you put your trigger on the chain first, your opponent puts Deploy on top, so Deploy resolves first (Rule 383.3.d.1 / 340.1). The Bomb dies, and its death trigger ("deal 2 to an enemy there") goes on the chain and hits your 2-might unit for lethal before Amateur Recital's ability resolves.

That damage alone doesn't kill the unit yet: a cleanup can't happen while chain items are resolving, so the kill becomes an outstanding task (Rule 321). Amateur Recital's ability then resolves and can legally move the damaged unit to Base. It doesn't save the unit, though — lethal damage stays marked, and the next cleanup kills it wherever it is, Base included (Rule 323.5.3b). If that was your only unit at Amateur Recital, you also lose control of the battlefield in that same cleanup, and you keep the point you already scored.

This is my interpretation based on rules 383.3.d.1, 321, and 323.5. No official FAQ exists for this specific interaction.