I can help with that.
I love the Combat.
There are inefficiencies within the system. Black Mage is boring and needs more skills with unique mechanics, or at least the illusion of a decision to make to be engaging. Bard has awkward moments of "lull combat", where they basically don't have a lot of things to do, but overall feels decent.
All fights are currently limited to the terrible server response, so the introduction of fast-paced mechanics is very difficult for them to do.
How will crafting look when all the animations are shortened? Will it look as ridiculous as when they are repaired? I'm personally not convinced that the form of crafting we have now is the best and most engaging solution that can be developed.
There's a lot of storylines.
This is something that can only be determined after 2.0, but there are huge quality control issues with the main scenario campaigns. The quality isn't consistent, and it doesn't always feel like it was worth your time or advanced the story. Hopefully these are being completely overhauled. There are also countless default quests that rely on a dragon being present in the story, but you never get to see the dragon because the model wasn't created. Examples I can think of off the top of my head are quests involving Brother Telyn and Damieliot. There's also big issues with the over-use or complete misuse of certain music tracks within the quest presentations. Mechanics and battles within the vast majority of these quests themselves are utter rubbish. The best example would be the obvious parlay mechanics, but extends to "run 30 minutes to kill a wolf" or "pretend you have these magical sylph abilities that you don't actually have".
There obviously aren't any real engaging storylines below lv 30, and I think that's a major problem too. They don't have to be world-shattering, but they need to exist.
There is plenty left to be critical of, even within the things you have no complaints of, and hopefully they've addressed these issues for 2.0.