That's how I drive to SA (except for the Copperas Cove part), it has a lot more hills (if you're into that it's the way to go). Unless you're just a glutton for punishment and feel it necessary to go to Temple for some reason; I would go 217/215 to 84, take 84 west to 116 (skirt the west side of Ft. Hood). After you hit Copperas Cove head SW on 190 to 2657 and take that to 183 which will take you straight into Austin. Once you hit Austin ask some of the locals, they can probably point you to a safe bike rout to the Capital. In my opinion that will be a much more visually appealing rout than through Temple.