As a player who has had to reduce the difficulty to not get killed 8 times before I manage to win against seeming random boss fights (some but not others), I'm working on my smithing and enchanting to try to get my defenses up to compensate for my lack of dexterity. So I'm glad the system allows me to try to compensate like this.

I buy iron ore from the venders and do some daggers and enchanting after each adventure but don't just grind at it endlessly. So far it's worked pretty well. I'm making better stuff than I'm finding and I'm doing a bit better in fights.

Alright, here are my thoughts:

Destruction: Of course Destruction is underpowered, I mean come on! You get RIDICULOUS spells like Blizzard and Fire Storm.
Conjuration: Isn't a good tree to compare with other trees. Mostly I consider it as a "distract the enemy" kind of magic.
Illusion: Similar to Conjuration. Used to distract the enemy or stop yourself getting swarmed by them.
Smithing, Enchanting, Alchemy: Do agree the crafting skills are a little OP. But mainly just levels up too fast.
Lockpicking: It's definitely worthless with the Skeleton Key, but you lose it if you want to finish the Thieves Guild questline. My opinion is that it levels up way to slow after level 50.
Archery: Overpowered but it's designed to be that way because most enemies will run at you to fight, which means switching to melee so you do more damage and take less hits overall.
One-handed: Dual wielding 1 handed weapons is definitely [censored] in blocking, but that's spread evenly with armor. You want to do more damage? You need good armor.
Speech: If you're having way too many items to sell and the merchants aren't rich enough, the later perks are quite good. Plus, it's basically a cheapskate's way out of not wasting gold on bribes (like me).

So most of the OP skills are connected to the UP skills which evens them out. Conclusion: Perk system isn't THAT flawed/bad.

30 hours? By reading your post, I can tell you're quite the skyrim master.

Only 30 hours and you think you know every perk tree? Cocky much? 30 hours doesn't even get your past 50-60 in any skill unless you farm that one skill for those 30 hours.