How brutally difficult does this get?

[Andrew R]

I'm about 30 hrs in.

[Chocos Ramabotti]

Depends on the order you tackle the objectives. I would recommend doing the Omelette Sidequest first right from the get go, then you might tackle the harder version of the Money Tree, both are quite easy compared to Vam and the Chaos Serpent. Then you can go to the Uzra traveling the world.
Afterwards I would try to rescue the party members in the following order:

Ez, Zinikr, Tan, Kina & Cheryl

The boss you fight when trying to save Kina & Cheryl is especially hard and the first major roadblock in Part 2. The damage output of Tan will surely come in handy.

Afterwards every character has its own quest of 2 quests at minimum that progress other questlines sometimes and 1 additional optional quest where you achieve the 2nd most strongest weapon of an character.

Also every boss you fought in Part 1 will eventually come back in a harder version, not in the order you might expect. Some early bosses in their hard version might be more brutal than the later ones.
That also means your previous tactic against the Lyranodon will no longer work, as he can already push you down with one full charge.

You will have to use the full repertoire of the abilities your characters possess.

[Andrew R]

I'm pretty much ready to throw in the towel and start Lunar. :P

Can't figure out the Zinikir fight with the elements...

[Chocos Ramabotti]

Originally posted by Andrew R:

I'm pretty much ready to throw in the towel and start Lunar. :P

Can't figure out the Zinikir fight with the elements...

You have to hit the enemy when the rocks around it don't allign with the trajectory of your attacks it's a timing matter.
When the rocks are so small that you can't time the hits anymore, use the "Vacuum" from Ez (that's why you should better save him first) it swallows up all the pieces.
If you don't have the skill on the board, you can always reskill.

There is also one black gem that allows one of your character to pierce the rocks regardless. Look for the "Pierce+" trait.