Here's the more literal translation I came up to, with some notes.

BALLAD 15 - BY WHICH FRANÇOIS VILLON CRIES MERCY TO EVERYONE

To Carthusians and Celestines monks,
To beggars and devotees,
To loafers and shoe slappers/scamps(1),
To servants and cute/elegant girls
Wearing surcoats and tight-fitted tunic dresses,
To presumptuous transfixed with love
Without embarrassment wearing tawny boots(2),
To all people I cry mercy.

To young girls showing their nipples,
To have widely more guests,
To crooks, troublemakers,
To tumblers dragging trunks,
To scatterbrains, to jokers,
Who go whistling in [groups of] five and six
To widows (3) and puppets/Virgin Mary figurines (4),
To all people I cry mercy.

Except to the traitor mastiff dogs(5)
That made me eat hard [bread] crusts,
Chew many evenings and mornings,(6)
[So much] that now I don't fear three droppings(7).
I'd make farts and burps for them;
I cannot, for I am seated.
Furthermore, to avoid quarrels,
To all people I cry mercy.

Let them have their fifteen ribs (8) crumpled
With big, strong and massive mallets,
Clubs and such balls.
To all people I cry mercy.

(1) young men who wanted to attract young ladies' attention would go out of the church flapping their "patins" – (Shoe consisting of a plate -generally wooden- more or less richly decorated, resting on the ground by a more or less thick sole, and fixed to the foot by means of straps. - Other sources say it means "galopin" = scalawag, scamp
(2) Tawny boots were actually laced ankle boots and the tawny color showed publicly that the person was in love/a lover. -I'm not really sure "méhaing" to mean "embarrassment/shame" but the primary meaning of "mutilation" doesn't seem to fit.
(3) Some versions have "marmousets" = young children
(4) A "mariotte" was an image / figurine of Virgin Mary (hence the word = "little Mary") or a puppet. Could it mean here well-behaved young ladies? Mystère et boule de gomme !
(5) The bishop of Orléans and his officers who jailed him (in Fr.).
(6) Some versions have " Et boire eau maintz soirs et matins," = "And drink water many evenings and mornings"
7) I couldn't make three droppings
(8) At that time people believed men had only 15 ribs while women had 16 because the Bible says that God took a rib from Adam to make Eve.