how did hank not know???

i’m watching breaking bad right now and is it just me who thinks hank was an idiot for not realising sooner than Walter is Heisenberg? it was so obvious.
1. his connection to jesse pinkman, while jesse was a suspect
2. the gas masks found at crime scene went missing from walters lab
3. the way he interrupted hank to block his view of the fake Heisenberg when badger got the wrong bench
4. the w.w in Gales lab notes
5. the fact walt was a chemist
like be so for real