Deiwos AND dyews

A real basic question which shows my lack of linguistic skill, but I
have gotten tired of saying to others, "Oh the terms are all
cognates" without being able to express exactly how they are related.

I took the following from the AHD online (bits omitted for brevity):

ENTRY: dyeu-
DEFINITION: To shine (and in many derivatives, "sky, heaven, god").
Zero-grades *dyu- and *diw-.

I. Basic form *dyeu-, Jove, the name of the god of the bright sky,
head of the Indo-European pantheon. 1. Jove, jovial; Sangiovese, from
Latin Iovis, Jupiter, or Iov-, stem of Iuppiter, Jupiter. 2. July,
from Latin Ilius, "descended from Jupiter" (name of a Roman gens),
from derivative *iou-il-. 3. Vocative compound *dyeu-pter, "O father
Jove" (*pter-, father; see pter-). Jupiter, from Latin Iuppiter,
Ipiter, head of the Roman pantheon. 4. Dione, Zeus; dianthus,
Dioscuri, from Greek Zeus (genitive Dios), Zeus.
II. Noun *deiwos, god, formed by e-insertion to the zero-grade
*diw- and suffixation of (accented) -o-. 1a. Tiu, Tuesday, from Old
English Tw (genitive Twes), god of war and sky; b. Tyr, from Old
Norse Tr, sky god. Both a and b from Germanic *Twaz. 2. deism, deity,
Deus, joss; adieu, deific, from Latin deus, god. 3. diva, divine,
from Latin dvus, divine, god. 4. Dis, Dives, from Latin dves, rich
(< "fortunate, blessed, divine"). 5. Suffixed zero-grade form *diw-yo-
, heavenly. Diana, from Latin Dina, moon goddess. 6. Devi; deodar,
Devanagari, from Sanskrit deva, god, and deva-, divine. 7. Asmodeus,
from Avestan dava-, spirit, demon.

I am assuming the Vedic Dyaus comes from the dyeu stem?
Do the Baltic and Slavic Dievas/Deivs come from the deiwos stem??
Could someone express the rules which govern the linguistic changes
as the term evolves from deiwos to Tiwaz in both Anatolian and
Germanic???

As always, I am in you debt folks!
Aydan