garage door track support bracket

I noticed the metal supports that hold up the track at the back are not completely secured to the ceiling. Is it normal for them to move from side to side when pushed. By this I mean if you were looking straight on at the door, they move to the left and right. Is this a necessary play for the smooth movement of the door up the track?

Also, there are gaps on both sides of the door where it meets the walls. How can I minimize the cold air draft to keep the garage a little warmer? Thank you.

 

The supports at the rear of the track should be fastened securely thru the ceiling to a rafter,and consist of three pieces(one vertical,one horizontal,one angle). A side brace should then come off midpoint or lower from the vertical strut, and attach to the ceiling strut at least 8" from where the vertical strut is attached. A door should be held firmly so that the top rollers do not slip out of their hinges.
pre-punched 1 1/4 x 1 1/4 angle iron is the standardand. It is available at most hardware stores and door company's.
As far as sealing the door, a piece of trim is used that has a rubber flap on one edge. The trim will be nailed to the woodframeon the outside,with the flap sliding up against the door. When making your cuts for the jamb and top take a poket knife and cut thru the flap about a 1/2" longer than the trim piece. then seperate the flap from the trim down to your cut line so that when the trim is nailed in place the flaps will overlap each other. I would suggest calling some local door companys since it is available in many colors. You might find one you dont have to paint. Ask for stop molding with weather seal.