Bulb shield does look pretty good.
Loop is probably OK too.
Clamp I wouldn't trust.
Best thing about setup shown in OP is it's not accessible to the birds,
so less likely to get knocked loose and if bulb shatters less likely for glass shards to be accessible to birds consumption.
BUT it is on the door, so hopefully you have another access point.
It's going to be -10°F here tonight, was zero last night....
....not using any heat except for waterer,
but will give some electrolyte/vitamins for a boost.
Sorry dude, had to add that.