Hello Vikky
First of all, Good luck with your application to Columbia and other schools. As for your question on the 'conversation' with the adcom director, I spoke to all the admin persons of all the schools I applied to. All of them gave the same reply,
'We need to look at the complete application' . It is true that they will not be able to judge us with the limited information over a 30 to 60 minute conversation. Their words are general and in no means to be taken positive or negetive.
And you will never know unless you apply to them, as you will have no idea about the competition you are facing for that school. I applied to Cornell and LBS after talking to the adcom, who said the same, Yeah...but the reason I applied to them, though they were long shots (with a 640 gmat), was not to regret. You know, there is always a question
'ONLY IF I HAD APPLIED...'.
One valuable suggestion from my side, do not wait for the deadlines. It is much much much better to apply in the first round. I applied in the last round for LBS and got a ding. Once you complete the apps, apply to them. Go ahead dude... Columbia is a fabulous school. Do not look at the high application fees, you can make that money back after some hardwork and overtime

. But if you get it....dude...you will be happy to get in to your dream school. Again, only if u r confident with the school. Let us know your profile and we may be able to give a rough estimation, though it shud not be taken as a 'decision'. I hope this helped. If there is anything let us know.
Regards