Just curious.
Not an answer really, but I type my smiled like this (: and I read LTR (usually)
d:
(:
Japanese is read down from the right then left to next column … so their smilies aren’t slanted. 
^_~
>.<
Traditionally, yes, but left-to-right (horizontal) is common in modern use. (As is Chinese).
To the OP – I don’t read any languages like that and was waiting to see if a native speaker had a definitive answer – I can say that from researching internationalization / localization that when western names / company name abbreviations (for example) appear embedded in Arabic text they remain written left-to-right, e.g.
word#5 word#4 IBM word#2 word#1
If the smiley is treated as a logogram (rather than a collection of 3 punctuation symbols) then I’d expect it to remain in the familiar form / adopted form rather than getting reversed, however the Japanese tend to use their own smilies as Turble showed.
For Urdu, yes.