If there was no friction (i.e drag, air resistance) Would'nt aeroplanes be faster and so travel in less time. They would be more effecient, right.....?

How would they take off or land??? You need friction in the tires. And if you follow the chain reaction backwards, humanity would not be manufacturing stuff coz we count on friction for simple things as writing on pad, holding onto things.

Besides if the plane is air borne-- already by some magic-- How would you stirr it without wind resistance??

No air resistance, no lift, no need for airplanes. We'd have to come up with some other way to defy gravity huh?

How would you control the aircrafts? There would be no reaction when you activate your control surfaces, or apply the brakes etc.

For landing thrust must be less than drag, and lift must be less than weight.

Yes drag is important.

Without drag and air resistance, there would be no lift. The plane would not go anywhere. Lift and drag are flipsides of the same coin. You cannot have one without the other.