[Ryengoth]

You won't really know until you pull the timing cover. Wait and get a parts list first based on the carnage. Most likely you will need a full set of plastic guides at a minimum. I find it hard to believe that the chain snapped like that. If it did, you may be buying a new timing gear (not a cheap part these days). There is a timing chain for the cams and a balance chain for the balance shafts. I am finishing up a rebuild on a B234I on my YT channel. I did not go into a ton of detail on the timing bits, though, since it's a simple process if you follow the book. All of the B200 series motors have the same timing setup style as well and there is content out there for it.

 

[Ryengoth]

It will be fairly obvious once the cover comes off. The tensioner should be fine but the spring inside may need replacing. A sharp putty knife is helpful breaking the seal on the cover.

 

[Ryengoth]

Boroscope the cylinders before you buy it?

 

[Ryengoth]

The only issue I could see from looking at the intake online (mine is not a turbo) is that an increase of say 20% or more of equivalent CFM from a larger turbo would suggest more surge area in the manifold to buffer the charge. I know there are folks out there with plenty of experience with performance mods on these engines, but possibly not on this thread since the topic is different. Post a new thread?