Just for your info, I have received via a Swahili site the one as yours and also the following:
Anaongea kifaransa kwa ufasaha.
Anaongea Yuruba kwa wepesi.
Anaongea kiswahili bila shida/bila matatizo.
I think that 'Anaongea kifaransa kwa ufasaha' is literally the best one, but I am still not sure which one is commonly used.
'sanifu' is 'standard'. eg. Kiwahili sanifu as opposed to its numerous variations spoken by indyviduals, NB Kiswahili has been granted recently an official lanuage in Kenya, but according to Kenyan newspapers, the problem is that even many PMs speak 'their own kiswahili' bit different to the 'sanifu'
'wepesi' = quickness, lightness (in weight) haste, ease
while 'ufasaha' = facility, clarity (of pronounciation) , purity of style, eloquence, elegance (esp. in speaking and writing
Oh, that's nice to know Petro M, thank you very much! I agree with you that "Kwa ufasaha" sounds best, but as to which would be most common, having lived in a swahili speaking environment for many years, I would say "bila matatizo". It's not nearly as eloquent, but it is more common orally. The others are great but more literal, more formal.
And English Speaker, asante sana = Thank you very much.
You're right, it's in Lion King.