how does a small tsu after a ki effect the sound of ki?

Answer 1

Are you asking about Japanese?
If so, a small tsu is pronounced as a 'silent syllable'.

"kitte", a postage stamp, is a 3 syllable word ---ki-t-te
when you pronounced the 2nd syllable, your toungue is pused toward the upper gum and you prepare to pronounce the 3rd syllable without making any sound there. You hold the silent for the same time as one syllable.

So, kitte is pronounced just like ..ki-(silent)-te
When you pronouonce the 2nd syllable, you abruptly stop the sound of the 1st syllable with your tongue at the position to pronounce "t" but not yet actually pronounce it.

Try actually count 3:
Count 1: pronounce KI
Count 2: be silent with your tongue prepared to pronounce T
Count 3: pronounce TE

This is how we Japanese pronounce what's called a double counsonants.

Answer 2

It makes the sound of ki shorter. It stops the ki sound abruptly.

Answer 3

yes, kinda like how you pronounce kitchen