As far as I know, "richtig" has more of a guttural sound, which makes it easy to distinguish between that and wichtig. For example:
The pronunciation of "r" differs depending on where you are from. Google translator and duolingo pronounce it as a voiced uvular fricative. I pronounce it as [ɾ], others might pronounce it as [r].
'o.O I never knew that, ... are you absolutely sure about that? xD It's kinda hard to wrap my head around.
Wow... so it's true! xD I've yet to really notice it when speaking to German folk, ... I'll pay attention next time I'm chatting to my Online German buddy.
One year later, and I've still never noticed this. xD
In German we hardly distinguish between "w" and "v" (and sometimes not between "v" and "f") and that's why some people mispronounce the English "v".
No, it isn't. 'You are important for me' : du bist wichtig für mich. 'Zu' is used with some particular verbs. For example: Das gehört zu mir -> that belongs to me.
I definitely wouldn't rule that out. I disagree with Krueckauer too because "weighty" can mean important. See definition 3: http://dictionary.reference.com/browse/weighty?s=t