Spoilers galore!!! Then again, if you're reading this thread, you're asking to be spoiled, so the warning is kinda redundant. I'm going off of memory on minimal sleep, so I'll try my best with this one.
Well, I suppose it's worth mentioning in this thread that the last time, and perhaps the only time, the Prince gets to roam around by himself is after you overthrow Stormfist and Sialeeds liberates Rainwall (the latter not being required, but gives you more freedom to roam), but before you enter the guard room to start the war against Sol Falena.
It's kind of a point of no return in a sense.
-Lyon isn't following you around.
-Neither is Miakis.
-Georg is still available.
-Maximum party customability.
-Luserina is still in your castle, readily available to swap out party members.
-Dinn isn't available.
-Lyon isn't available.
-One of the Beavers aren't available (oh wait, cons! Sorry)
-Flame Array Chains and Windspun Armor can only be bought in Sol Felana (Flame Array Chains can be found off of Blue Salamanders on the world maps)
If you decide to move onto Sol Falena, afterward Lyon will force her way into your party, as will Zweig. Can't quite recall, but I think somebody else as well. You either lose Georg right away, or very soon. Luserina plants her butt outside of the thrown room in Sol Falena's castle, making swapping party members an absolute b... pain. To avoid this, just stay out of the guard room until you're ready.
I'm sure I'm missing something, but I covered the bulk of it. Probably common knowledge and not what the thread starter is looking for, but it has a place here.