Custom Lineage: characters who are part elf can get the Elven Accuracy Feat? Can customs use racial feats if it falls in line with their backstory?

Burning hands is both a “a thin sheet” and a cone. Which is correct?

Is the bard’s Jack of All Trades intended to apply to initiative?

I see that features from Way of the Sun Soul has different writing on Xanathar’s

Can a Simulacrum of a legendary creature use its legendary and/or lair actions?