where can you find all the non echo stuff and the low tide/hide tide
In the mermaid haven, speak with the locals to discover the underwater temple. Then you will need to draconic shove the gates open.
Once inside, the direct route to low tide is down north north, the direct route to high tide is up north north. Depending on the sun and moon paths you did, one of these may be blocked.
Wheel puzzles requires both wheels to be correct to unlock something. There are no other puzzles in the temple, the rest is set dressing. The Tides story goes more into what the temple is all about, and in some cases the tides story is required before you can solve the temple wheels.
The answer for the wheels are "Fii" and "Caputo".