Ok here is my overall critique. Note that this is my own opinion and others will likely have their own opinions as well.
Especially since someone else I know is using this class in a PbP game (or signed up to use it)
Okay starting off:
First thing I notice is the wide stretchy screen. Not enough to make me need to scroll but it's always good form to Spoil every picture for reading discretion
1/2 BAB and 1 Good save, this is not a Combat class at all, especially with the D6 Hit Die.
Which fits with the Minion role
Looking at the template there doesn't appear to be any dead levels (though I am wary of the Light/Sound/Power etc. Bricks) so that is a Plus.
Moving onto the skills I can see a thematic and game use for all the skills there except Use Rope. Why did you add it? Use Magic Device applies too, as Lego is innately non-magical though that can be explained a bit more.
So you can make and deconstruct with no penalties, sounds alright.
Bonus to Craft = to level, also good. Though does Craft give any bonuses from having a really high score? Looking down in Models it doesn't look like it. It only gives a cap on the number of bricks used (which is somewhere in the thousands, limiting the bigger and more expensive options)
The Brick-Builder can salvage another's lego Model's with a Disable Device check, DC Brick-Builder's level. So a 10th level Brick Builder has a DC10? Or did you mean 10 + Brick builder's level. Because sinking one rank into Disable Device lets you pretty much auto-salvage any other Brick Builder's things.
3 Silver pieces for a Minifig *level
At levels 3-8 you will have a swarm of them, simply moving them from room to room would take minutes of commanding but you will never run out.
And since it's a +5 only when needing to make a Concentration check the Brick Builder will take control of the Action Economy with a swarm of 40+ Minifigs. Which (at level 5) cost 1.5 GP, so 60 gold.
There needs to be some sort of limit, a Hard cap (not a soft one, or one that only applies some of the time). Maybe 5 + 1/2 level?
Who would ever use a Light Brick in a weapon Or at all? 1d6 extra Fire damage is nothing, it's much easier to simply use them as inexpensive Torches or just never buy them at all
The same goes for Sonic and Power. Maybe not Power when there are things that require it to function.
Soul gets the same pass as Power in that there arent anything that needs power
Needs filling in
Starts at 2, goes up to 10 by the end of the class, since they follow instructions they would best be used in repetitive tasks every round (like Reloading) but their lack of numbers makes Animated Minifigs valuable compared to the expendable Normal Minifigs
Either more of them, or make it a basic upgrade to the Minifig would be best (maybe an optional add-on that adds to their Pile of Bricks if you implement that feature onto them?)
-5 Character level is good, when having 4 Cohorts it can get OP if too close and useless if there isn't enough class levels to make it competitive
I do like the change to Character level instead of Brick Builder level
I am unsure of the standard times for making a Lego Model, but cutting it in half seems like a fine ability
5 Autonomous beings at any 1 time. Discounting your 5 Cohorts of course.
This number should probably be bumped up.
Telekinetic Is a good upgrade, letting you have LoS rather than Touch to assemble it
Body of Bricks:
Can you list the traits considered a positive and which are 'drawbacks'?
And 100,000 bricks a day is generating 10 Million GP of profit by selling off Soul Bricks. Maybe add an addendum that the bricks may only be used by you to create Lego Models and not sold off for money. And reduce the number of bricks produced (maybe also increase GP-Brick conversions and reduce some of the larger costs of Lego Items)
Please detail the Minifig Swarm the Builder can become. And I do like the +1 level.
Minifigs: What advancement do the little guys get for their HD increase? Construct traits? What level do they grow in size if they do at all
Minifig Armour/Weapons: Do they stack? Can one apply Minifig Armour twice to gain a +4 Nat Armour for 2 Bricks? or 2 Weapons increasing the size by 2?
You do realize it requires a base 110 Craft check to make a basic Vehicle right? 10,000 /100 = 100. 100 + 10 = 110. And to increase it by 1 size adds 900 to the craft DC.
And even if it didn't, where would the Builder get upwards of 15k bricks for a good vehicle before lvl20?
And why is the vehicle speed stuck at 40ft? and Average maneuvering for the fliers
Weapons: 1 brick/shot is a little much. Maybe 1 brick /quiver? with the quiver having 10 shots in it
Skills: So it has max rank -3 -multiclassing? Right up until the Builder multiclasses or hits 20 they will have a full assortment of independent Skill-Minifigs running around doing the whole range of skill-assortments
Feats: 30gp +30gp/feat? Yes please. Especially when I hit lvl21 and get the prereq for Epic spells. Hellooo Bracers of Perfect Two-Weapon Fighting, Epic intelligence x10 and as much Toughness as I want