Yes the flame is adjustable.
yes, cast aluminum to look like weaving
yes the are a clear glass bead.
Comes with Fire Glass ... the little oblong marble looking type. I purchased more to fill it in, the amount in the kit was a little shy of what looks good, in my opinion.
***Correction... 2-1/2 in gap. But I really don't notice it, ever.
Not advised ... This baby puts out too much heat to be under cover unless there's a lot of head space & a fire retardant ceiling. Might not look like much, but this is outside with a little air movement. Still nights, the flame is easily 18-24 inches, and it's hot well well well above that.