Raising of [e] to [i]

[ˌkəˈxʷiː]

Shift of labialised velars to labiodentals (with labial offglide retained before front vowels):

[ˌkəˈfʷiː]

Nasalization of long vowels. (Is it okay to do this?)

[ˌkəˈfʷĩː]

Eh, doesn't make a whole lot of sense, but it's not the most implausible sound change we've had here so far. Besides, I dislike it when features are simply lost without a trace, so I'm more than happy to have nasalisation back here.

/ŋ/ ephenthesis after nasal vowels in hiatus:

[ˌkəˈfʷĩːŋ]

[ˌkəˈfʷĩːŋk]
word final nasals become prenasalized voiceless plosives.

Initial [k] becomes [p].

[ˌpəˈfʷĩːŋk]

Elision of unstressed schwas

[ˈpfʷĩːŋk]

[f] differentiates to [z] (retaining labial offglide).

[ˈpzʷĩːŋk]

Not sure this is a likely change so ignore it if it's not.

Syllable initial [p]s assimilates into fricatives when no vowel is present.

[ˈzʷĩːŋk]

Again, I feel I must point out: This isn't a letter-substitution game, it's sound change game. How likely is an unconditioned change of initial /k/ to /p/ in a language? (Yes, they're both voiceless plosives, but produced at opposite sides of the mouth.) If we're going to throw all phonetic plausibility out the window, then the game becomes essentially mechanical and mindless.

Diphthongisation:

[ˈzʷẽĩŋk]