pronunciation - So, "carrots too" (/ˈkærəts tuː/) can sound like "Carrot Sue" (/ˈkærət suː/), right?

Look at this video at 1:09 (Source). The man said "carrots too" /ˈkærəts tuː/ but it sounds like he said /ˈkærət suː/. The /t/ got omitted completely.

However, I don't see people omit /t/ in "stamp" /stæmp/ (Source)

I have another example. The /t/ after /s/ got eliminated completely. See this video at 3:25 (Source): "...wasn't the best idea" "/..best aɪˈdɪə/" became "/..besaɪˈdɪə/".

So, when we see /st/,

1. can can omit the /t/? or




2. do we have any rule as to when we should omit /t/ from /st/ and when we should not?