I am late to the party. I am 110h in and just completed chapter 9.

I feel like now is time to complete all remaining side quests and try to pull few more rare blades.

So far, the game has been a joy to play. I really like the characters/story as well as the exploration aspect. Story fights were always a bit easy as I was overleveled most of the time due to too much questing/exploring.

A few questions :

- Is chapter 10 only cut scenes with boss fights or is there a bit of exploration as well ?
- What is the best way to farm Rare/Legendary Cristals ?
- Is there a way to farm the item to change a blade's driver ?
- Is there something worse in this world than Ursula's side quest (I think I am almost there...) ?

Damn, I don't want to finish this game...

- Is chapter 10 only cut scenes with boss fights or is there a bit of exploration as well ?

Its basically just cut scenes and a boss fight.

- What is the best way to farm Rare/Legendary Cristals ?

If you can do it, go fight Reeking Douglas in Gormott.  He is level 104 and can drop a rare and a legendary each time you do the driver combo (Break > Topple > Launch > Smash).  Make sure you seal him with a dark orb to prevent his summoning friends as your first act and you should be fine.

- Is there a way to farm the item to change a blade's driver ?

Not that I am aware of.

- Is there something worse in this world than Ursula's side quest (I think I am almost there...) ?

No.

Speaking of chapter 10, is there any opportunity to grind non-boss enemies before the final boss? 

I'm not yet high enough level and I'm so sick of grinding the robots at the end of chapter 9.

Yeah, I personally never understood that too.For me its like complaining, when you are playing a story driven game, that a book has too many pages in it.

The game gives you a prominent warning before you cross the point of no return.  And even then it's not really a point of no return.  If you wish to grind, you may fast travel away to do so.  The game is pretty generous in that regard.  However, I if you are level 65 or higher, the real key is less levels and more your Aux Cores, Core Chips, Blade Affinity, and Character Affinity charts.  Truth be told, levels are not nearly as important in 2 as in 1 or X.  I can take on normal enemies 12 to 15 levels higher than me and bosses 5 to 10 higher.  The fastest way to build blade affinity is side questing so that's a worthwhile focus as it also affords you bonus XP.  Also, I recommend getting 3 rares on every driver if you haven't already.  For DPS, Herald is fairly easy to obtain in Tantal, is very powerful, and very straightforward to power up.  If you don't have her, grab her before any grinding and questing and put her at the front, you'll easily build her up.  Vess is a good healer easily gotten in Torigoth.  Some good sidequests can be found in Mor Ardain btw.  

Also, if you are using Tora, 1) unlock Poppi QTpi, 2) get the technical manuals (seriously, look the locations up, at this point it will just be easier for you), and 3) after doing those hit the Tiger Tiger.  Doing those will let you power up Tora considerably.

Also, make sure you have good accessories equipped.

Yes right before the elevator to the Final boss area there is a room that is basically filled with large enemies to pound on that you can approach one by one and gain experience. 

Also at any point you can break immersion and just skip travel to another area to grind.

Thanks everyone; did some grinding and sidequesting and boosted myself up to level 72; gonna give chapter 10 a go now and see how I fare.

Also ZOMG I freaking fangasmed when opening cutscene of Chapter 10 confirms this is a direct sequel to Xenoblade 1! Hearing Adam Howden and seeing the Phase Experiment Facility again was such a nostalgia rush. Looking forward to seeing how the storylines of the two games tie together.

If you only saw the opening cinematic, then there is a great(and outside the opening cinematic, the only one that connects both games) twist that will happen really close to where you are.

Can't wait! :D Hopefully will get to play it tonight; frustratingly my little brother is watching me play through it so I wouldn't want him to miss the story, but his sleep cycle is outta whack atm so I don't know if he'll be up for it. Might be a few days til I can continue. :(

Finish it then tell him to youtube the parts he missed!