I install garage doors and openers for a living... Most people will charge you 80 to a hundred to install an opener.
The opener you purchased is a pain in the ass to install (too many parts) The screw drive system isint very good.. its louder than a straight chain drive operator and if your door doesent operate smoothly then the opener doesent always wanna shut the door.
If you have a wood door you dont really need any extra bracing to secure the top section but if its metal it is best to install a peice of punched angle spanning the whole top of the door.
Home depot has Chainberlain 1/2 hp chain drive operators for 220.00 tax inc. personally i would return the genie screw drive.