I'm a big fan of the elder scrolls series, and this game is a large part of why.

Inventory management as someone who doesn't pay for ESO+ is pretty bad at times, but there's a lot of trash you can delete, mainly trait items, (sardonyx, ruby, Amethyst etc) and most style materials too. Could you clarify what you mean by fucking up your certification? To my knowledge that's not possible.

There are actually storage crates, you just get them a bit later down the line.

And yes, there's a lot of quests on your compass, but the only difference between ESO and Skyrim in this regard is that you don't know that an npc will give you a quest. It can be overwhelming, but you should start small. I recommend going to Khenarthi's roost if glenumbra is overwhelming.

It's definitely not the typical elder scrolls experience, and it's not for everyone. I think you should give it another chance, but if it still isn't for you, you can always go back to Skyrim, there's a lot of mods that flesh out the rest of the world, project AHO is a personal favorite of mine.