The Last Remnant - Roadmap

Overview:
-Estimated achievement difficulty: 5/10
-Offline: 22 (1000)
-Approximate amount of time to 1000: 90-110 hours
-Minimum number of playthroughs needed: 1
-Number of missable achievements: 3: The Fallen, The Final Instance, The Last Remnant
-Glitched achievements: None

Introduction
The first thing you'll want to do is know what you're in for while playing this game. First off, it is going to take a long time. Depending on how much you play your Xbox each day, it could be up to a month. Now, while actually playing, make note that there is a very specific way to level and strengthen your characters. Read all about it in this thread and make sure you follow its advice from the beginning to save you a lot of time and annoyance. Also print off or have handy the side-quest walkthrough found here. Some of the quests are only available for a short time, so be sure to do everything ASAP and try not to deviate too much from that.

Step #1: Properly Level and Play the Game
In order to get your 1000, you really have to level up properly or you may not be strong enough to beat the final boss without considerable grinding. Again, make note of the link I provided earlier. Also, in case you missed it at the top of the side-quest guide, there are certain leaders that you will need to have recruited to gain quests from later on. Hire the following characters at Guilds when they become available: Loki (Athlum), Nora (Athlum), Rhagoh (Calapalais), Caedmon (Balterossa), Glenys (Nagapur), Jager (Athlum). Be sure not to miss any of the notes in the side-quest guide or you might invalidate or pass up something.

Now, if simply follow the side-quest guide and continue to level at a good rate, it is really a straight shot to 1000 if you don't mess those two tasks up. If you want "The Last Remnant" to be your final achievement, simply save before beating the final boss and move to Step 2, then come back and finish him off.

Step #2: Random tasks
Most of the achievements will come as you play. One of the only you'll have to go out of your way for is a Battle Chain of 200, but save that for whenever you're really stat grinding, most likely later in the game. You'll also want to dismantle every enemy you capture (500 needed). I did the entire game and still needed another seven hours of grinding amoeba creatures in the Ancient Ruins before I got it. All the "random" achievements can be done at any point in the game, so don't worry too much about them. Just make a note of any enemies to watch out for or items you need to collect.

Conclusion
This game is a long haul and requires some planning ahead in order to get the full 1000 on your first go. However, as long as you follow the list of quests and power up your party appropriately then it is more a matter of time than difficulty.