Even with steel pipes you get problems with hydrogen embrittlement because hydrogen diffuses into the steel and can cause it to crack.

Helium does a pretty good job of that too.

If you're producing electricity in it, you can always bring some water up and use some of that electricity to extract hydrogen from the water to make up for any leaks.

It really depends how bad the leaking is since that dictates how much weight of water is needed to be brought up and electricity must be used for hydrolysis.

No worries, that only happens if there's a spark, like for instance some static electricity. Shouldn't be a problem here, surely this thing won't generate any of that.

For an autonomous platform with some sort of safety mechanisms for jettisoning the air bag if a catastrophic failure occurs, hydrogen does in fact sound like a way better and less scarce lifting gas.

Wasn't the way the Hindenburg burned due to both the Hidrogen AND the alumium oxide paint covering it?

Nah, it's perfect!