[aohige]

Originally Posted by sasuke706

somehow he's supposed to be an intelligent protag despite how frequently stupid he is about serious subjects

Whoa, hold up. What even gave you that impression?
The protagonist is NOT intelligent, he is a fool. This was established in the story from early on, and never once was it suggested otherwise. He even knows he's a fool. Everyone knows he's a fool. Heck, he's even been pointed out as a fool numerous times in the story by other characters.

There's also the part where he'll give Subaru a very promising buff, then it turns out said buff is actually completely useless. It's happened like 3 or 4 times.

Again, huh??

Spoiler:

The black magic cloud he gets served him very well, got him out of many situations before him losing his gate.
The Invisible God hand continues to be Subaru's sole ability to use offensive, and has been useful all the way to current chapters.
The Dragon blood infection is a curse, has barely been introduced, and as of yet we don't know what consequences it has.

Only thing I can think of that applies is his contract with Beatrice, which was only useful once as of yet.

I think you're actually bothered with one specific thing, and trying to fit everything else to that judgement.