Estimated time for 1000: 110-130 hours.
Minimum playthroughs: 3
Missable achievements: Not really as you can transfer all data to a new playthrough, but there are many that can be missed on your first play.
Glitched achievements: Eureka! and Little Mad Scientist are troublesome, but not broken completely.
Offline: 50 (1000)
Online: 0 (0)
Cheats disable achievements: No Cheats.
Difficulty affect achievements: No.
Preperations
Ok, you're in for the long haul if you want 1000 in Tales of Vesperia. I've gone to great pains (on my hands) of typing up guides for just about everything you could ever need. This will save you time. Lots of time. You owe me a cookie. Be sure to follow the side-quest guide closely or you will be set back at least 9-12 hours for another playthrough. Also visit this thread and have a look at all the threads linked there. Take note of anything I have told you to take note of.
Playthrough 1: Just About Everything
First off, follow the side-quest walkthrough that can be found here. This will get you many items that can only be received through these side-quests as well as many of the titles that can be missed. Make sure you are using a Magic Lens on every single enemy, especially the ones marked in red in the Monster Book thread. Also make sure to work on mastering all your cooking recipes and getting Raven as many skills as possible by switching out his weapon any time you get a new one with new skills. After you have beaten the game, reload your clear data file (the one with the star you made after killing the final boss) and continue to work on any titles or various monsters/items you feel like. Now go clear the EX Dungeon.
Now you'll want to farm at least 10,400 Grade with whichever method you prefer. I used the powered up Fell Arms and just killed low-level enemies outside Zaphias on Hard difficulty with two Blue Dice and a normal Dice equipped. I was getting 6-8 Grade each fight in about two seconds each. While doing this you will also want to finish mastering all your cooking recipes with one person and learning 100 skills with Raven. The "Rita Grade Farming" method may be a bit faster but you will fight less battles if you still need those two things.
Playthrough 2: Speed Run and Mopping Up
Start an EX New Game from the main menu, selecting your clear data file. This is where that 10,400 Grade comes into play. Buy the following: Max Items 99 (400), Items (500), Gald (1000), Titles (500), Monster Book (10), Collector's Book (10), Recipes (10), Cooking Level (50), Map Data (300), Craft Skill (10), Records (10), All Artes (1000), All Skills (1000), 2x Gald (600), 10x Exp (3000), 2x Drop Rate (1000), and All Skits (1000).
With this, you wil have every record of what you did in the first playthrough, including all the best weapons, armors, artes and skills to begin with. On top of that you will be earning 10x experience to level insanely fast. Now proceed to simply blow through the game. The only thing you will need to do in terms of side-quests is the first step to opening the EX Dungeon, which is visiting Phaeroh's Crag and the rift found there to speak with the Sage and stay at his house before entering Zaude, but after it appears. If you fail to do that (like I did) you will basically have to repeat this step.
The speed run itself should take 9-12 hours. Be sure to use plenty of Holy Bottles to keep monsters away. With the 10x experience, you'll level enough off required fights to be able to ignore the normal enemies. After that, visit Nam Cobanda Isle to watch all the skits, then go for the long grind to level 200 and 10 million Gald by playing the EX Dungeon over and over. Then grind out the rest of the Monster Book/Collector's Book and finish up your titles by doing the 200-man melee with everyone. After all of this, the only achievement you should need is the low-level challenge.
Step 3: Low-level Challenger
Start an EX New Game with your save file from Playthrough 2. Purchase everything you did the first time except swap the 10x Exp for the 1/2 Exp and add in the perks to increase max HP and TP. Again, you'll have all the best weapons, armors, artes and skills so this really won't be hard. Blow through the first chapter and kill off Barbaros, but make sure you are only level 14 when you reach him.
That should be your last achievement, but if it isn't, repeat the steps in Playthrough 2 and finish off any side-quests you may have missed or scan any enemies you may have missed or do whatever it is that you may have missed. Congratulations on one of the longest 1000's on the 360!