A broken mosaic of words

Question

In this puzzle, you'll have to rebuild words using the "pieces" listed at the bottom and place them in the grid provided below. Some notes about this puzzle:

1. The gray cells with the dotted border are cells in common. Therefore each one of such cells shares two words. The gray cells at the center, which appear without any particular border, are used by one word each (so, not shared, but still important for the solution, of course).
2. Words can go in any direction (i.e. not just $\rightarrow$ right, or $\downarrow$ down).
3. Words must follow the thicker borders when placed in the grid. The thinner grid is only there to show you where each letter goes.

4. When encountering a gray cell, the only permitted direction is forward. So if there is a crossing, go straight, if there is a "wall", either stop there, or start from there. See these two examples:

                                 

   ^{Note: These two are only examples of directions, they may not necessarily show the writing direction.}

   Here's an example showing two words (FITTING, SOLUTIONS) that cross each other.

   

5. When the grid is properly filled, the gray cells (including the ones at the center) will give the name of a famous artist. The name is ciphered, however it will be possible to properly decipher this name with the information provided.

6. The words in the grid can be theoretically split into some categories:

   • Words related to the name of the artist.
   • Words that seem to be related but are there to confuse you.

   • Words that are unrelated to the topic of the solution.

     However, don't worry: the number of words in these categories is in descending order (so most of the words will be related to the proper solution, while very few will be unrelated). This means that the more you solve, the clearer the puzzle is going to be.

7. Words may belong to any word category (proper noun, verbs, etc.).
8. The letters in the grid are cryptic clues, they do not indicate what letters go in those cells.
9. All the fragments below are used exactly once and none of them is to be considered an independent word. For example "tomb", while existing on its own in English, is to be considered a fragment in this question. The fragments have been created by using the Merriam-Webster dictionary to hyphenate the words. In case the word was not available, I chose the most common hyphenation (other services, etc). Also, in case of plurals, the -s is not separated, rather it appears along with the last syllable. Therefore "solutions" would appear as so-lu-tions.
10. Attention to detail will be key in solving this puzzle.

                    

The broken pieces:

a a al als an ard ary ba ba bac bal bap bi brism chus cus da dom du e e e en er er ere ex ex ge gen gin hearse i ian ile ing ital jon lad law laz laz lit liz mar mas me ment nas oc og phy pi quar quez qui quil ra rais re re rence ri ro roque rus ry sa sa sculp sex sis tam ten ter thes tiks tist tomb tor ty tyr u ve vi vir viv

The aim, as stated, is to solve the puzzle, however answers that will explain the relation (or lack thereof) of the words in the grid to the final solution will be taken in better consideration.

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Note: I did add the no-computers tag, however I'd like to clarify that this refers only to automatic scripts and the like. Using a crossword solver et similia (which you then check manually) is completely fine.

Answer 1

Our artist is

Michelangelo Merisi da Caravaggio (almost always referred to by his toponym rather than the two names used here)

and the words related to him and his name are these (two of them, marked [*], are name-based misdirections; the connection of the one I've marked [!] is rather indirect):

ba roque
bac chus
bap tist
bi og ra phy
sex u al i ty
da mas cus
en tomb ment
ex ile
ital ian
jon quil [!]
law rence
laz a rus
liz ard
mar tyr dom
me du sa
quar ri er []
rais ing
ro sa ry
sculp tor []
ten e brism
ve laz quez
vir gin

Most of these are

portions of titles of paintings by Caravaggio.

Some of the others:

He was a pioneer of TENEBRISM in the BAROQUE period, and a strong influence on VELAZQUEZ; he was the subject of an early BIOGRAPHY; his SEXUALITY is a matter of some dispute (and some scandal during his life); he spent some time in EXILE. The JONQUIL is a variety of daffodil whose genus is Narcissus, the subject of one of Caravaggio's paintings. And of course another Michelangelo was a SCULPTOR and a QUARRIER.

and the following words are so far as I can see unrelated:

a qui nas
bal lad
ba tiks
ex e ge sis
lit er ary
oc tam e ter
re hearse
re viv als
thes pi an
vi gen ere

though I suppose you could argue that

the other Michelangelo was a LITERARY figure, and for all I know maybe some of his poems were in OCTAMETER. I'm not aware that he was a THESPIAN who needed to REHEARSE, though, and I doubt he wrote a BALLAD or studied AQUINAS. But who knows? maybe he did.

(Confession: I had the following help from Alenanno in chat: when I had almost but not quite that word list, he told me I had exactly two words wrong; when I fixed it to produce the above, he confirmed that it was right.)

As ffao perspicaciously notes in comments,

the pqrstu labels give word lengths. That means that the choice of letter tells us basically nothing -- but, as again ffao guessed, the letter always goes at the start of the word.

We can place most of the words (I think 22/32 of them) by deduction, after which we need to turn to the enciphered artist's name. Of course

given the occurrence of VIGENERE among our words, that had better be the cipher we use. But what key? Well, from the words I was able to place deductively I got the following likely key letters: A-T-NTIONTO-ET-ILA. After getting over the foolish first impression that this should be Italian, perhaps scrambled up somehow, it becomes apparent that Alenanno really meant it when he said that "Attention to detail will be key in solving this puzzle"; the key is ATTENTIONTODETAIL.

This lets us place most of the rest of the words. There remain two places where we can switch two words without violating any constraints; I have confirmed with Alenanno that this is just a bit of underdetermination in the puzzle, rather than something that's meant to be resolved by finding some further message hidden in the grid or something.

The final grid looks like this: