Yeah you still have to land on roads, there's 1 reason and 1 reason only to get The type F, the Hidden dungeon that it allows access to. The dungeon - Pitioss Ruins - is unique in FF history, it has no enemies at all, the whole dungeon is basically a platformer puzzle and is actually quite well done tbh - though Noctis' jerky controls can make it frustrating as hell in parts. The reward for completing the dungeon is basically the best accessory in the game - I forget what it's called, but it's Noctis specific and basically allows you to dodge many attacks without even inputting the commands that flash on screen, it is obscenely overpowered tbh.
If you enjoyed the game at all then the post-game content is worth doing, if only because it has more "challenge" like previous FF iterations. I'm not sure I get what you mean above though, most FF games have post-games that are essentially nothing to do with the main story, all the arena stuff in FFX for example cannot be done you're a level of power that makes the end-game bosses extremely easy, same with FFXII and FXIII tbh, in all those cases the 'game' is basically done when you are powerful enough to do all extra stuff.
lv120 wasn't a thing when I platinumed the main game, but I assume the same exp tricks work really well, they abuse expericast magic and sleeping at the expensive hotel in Altissia. There's an item you can find (debased coins I think, or something similar) that can be used to make loads of copies of weak damage, high exp Expericasts. Make alot of these casts and then fight something with high HP that you know you can kill but won't die quickly, cast the magic over and over again and then kill it once you've run out. You should get hundred of thousands of xp if done right. Sleep at the aforementioned hotel for the 3x bonus for huge level jumps. I did the last 20-30 levels in 1 hit. As a btw I used the mark in the Fistful of Gil hunt as my opponent for this method, as it was easy to find from Hammerhead; I think their are better choices though. You can look up expericast levelling methods for what will probably be a better more exhaustive description, plus there's loads of video out there too,
This post has been edited by WinterPhoenix: 22 August 2017 - 10:54 PM