AUCTeX has support for multi-file documents, explained in detail in the manual (auctex) Multifile. After opening a 'master' file that includes many other chapter files, the reftex TOC command (bound to
C-c = by default) presents me with a complete TOC include all the sections and subsections in the included files. The reftex manual node (reftex) Table of Contents explains all the options.
The TOC comes with support for sectioning commands, and also labels. It doesn't appear to support displaying other environments, such as your BLOCKS, by default, but can apparently be extended to do so:
The section macros recognized by RefTeX are all LaTeX section macros
(from ‘\part’ to ‘\subsubparagraph’) and the commands ‘\addchap’ and
‘\addsec’ from the KOMA-Script classes. Additional macros can be
configured with the variable ‘reftex-section-levels’. It is also
possible to add certain LaTeX environments to the table of contents.
This is probably only useful for theorem-like environments. See Defining Label Environments for an example.
Here's what the TOC for one of my multi-file documents looks like, with file boundaries and labels both turned on:
File master.tex starts here
File frontmatter.tex starts here
* Contributions of Authors
File frontmatter.tex ends here
File intro.tex starts here
File intro.tex ends here
File lit_review.tex starts here
2 Literature Review
2.1 The Species
2.2 The Niche
2.4 Molecular Markers: Amplified Fragment Length Polymorphisms
Note that every line in the TOC is an active link to the appropriate location in a file.