This post is essentially a sampling of interesting pronunciation features in Cléire Irish. It is far from exhaustive. Standard Irish forms in brackets.

Lenited r

Where you could expect lenition for other letters a broad r sometimes becomes palatalised. This can be seen, for example, in “a reá” (a rá, “to say”), where the spelling is an attempt to indicate that the the initial r is slender. “do rug” is another situation where this occurs.

The past autonomous and the pronunciation of -adh

In Cléire the past autonomous form of the verb usually finishes in a /v/ sound, though it can also finish in a /g/ sound.
Do dúnamh/dúnag (dúnadh) é – It was closed.
Note, this is still normally written as “dúnadh”.
In Muskerry (Cork), it is the /g/ sound which is used, though the /v/ sound was once also present.
In Déise Irish (Waterford) you get /g/.
In West Kerry Irish you get a /x/ sound (broad ch).

You do get the g sound in “bogradh” (boglach, rainy weather), “glasradh” (vegetables or cold, damp and windy weather). However, “scanradh” is pronounced /scaurəv/ (something like “scamhramh”). In Muskerry this word is pronounced /scaurə/ (scamhra).

Medial bh and mh

-bh- and -mh- tend not to be pronounced when they appear in the middle of words, though this can affect vowel quality. Example:
tábhacht -> tácht (importance)
fómhar -> fór (Autumn)
lámhadóir -> ládóir (manual labourer)
nimhneach -> níneach (painful, poisonous)

This sort of dropping can be seen in the rest of Munster too.

Delenition

This is a really interesting one. When labial sounds come together (m,b,p) you can get delenition:
“im bhéal” (“i mo bhéal”) becomes “im béal”
This is easier to pronounce because both m and b are pronounced with the lips pressed together.

th- is delenited after n and s
an ceann tuas – the one up there
thíos agus tuas – down and up
This phenomenon can also be seen in Kerry and Muskerry Irish, and perhaps beyond.

Metathesis

This is the inversion of two consonants and it can be widely seen in Irish. Examples:
milseáin -> mísleáin (sweets, candies) – This form is also seen in Kerry and Muskerry, though not Waterford.
tráthnóna -> tránthóna (afternoon, evening) – This form is also seen in Muskerry and Kerry, though Rinn in Waterford has /tra:xnu:nə/.

Eclipsis of s

My favourite. If an s appears in a position where a consonant would normally be eclipsed you can eclipse it in Cléire Irish. For a broad s this becomes a /z/ sound (as in the English “zoo”) and for a slender s this becomes a /z’/ sound (like a voiced sh, or French j).
i zSasana (i Sasana) – in English
ag an zséipéal (ag an séipéal) – at the chapel

This sound used to appear in East Galway Irish.* Raymond Hickey (in “The Dialects of Irish) also makes an oblique reference to /z/ in Déise (Waterford) Irish, but I can’t find any examples; it’s certainly nowhere near as widespread as in Cléire Irish, at the very least.

Pronunciation of -lt-

The cluster -lt- is pronounced as if it were lenited: -lth-.
fáilte -> fáilthe
This is found in Muskerry and Ring (Waterford) too, though not Corca Dhuibhne (West Kerry), as far as I know.

However, -lt is pronounced as -lt, if it’s the (non-historical) ending of a verbal noun:
an fhinneog a oscailt – to open the window

Comments and corrections are welcome!

Sources:
“An Teanga Bheo: Gaeilge Chléire” – Breandán Ó Buachalla
“Cnuasach Chléire” – Breandán Ó Buachalla
“Gaeilge Chorca Dhuibhne” – Diarmuid Ó Sé
“The Irish of Ring, Co. Waterford” – Risteard B. Breatnach
“The Irish of West Muskerry” – Brian Ó Cuív
“The Dialects of Irish” – Raymond Hickey

*Hickey cites Ó hUiginn 1994: 559 for that.