I moved away from Austin almost 20 years ago, so much of the particulars of my information is going to be very out of date.
The bats are cool. They are under the Congress Avenue bridge, which is the bridge over Lady Bird Lake (Colorado River), in the middle of the city. I’m not sure what time of year the bats are around, so check on that (google, etc.) but they come out at dusk. Bat picture, bat picture, and bat picture. Because it will be dark, and the bats are black, the only way to take pictures is to shoot into the air with a flash and hope you get something.
Most activities in Austin revolve around drinking beer, listening to music, and eating food (probably barbecue or Mexican). At the time I was there, the Austin Chronicle, the weekly free paper, was the lister of all things music related. Go to the website and look up the music listings for the days you’ll be there and see if anything catches your eye.
Austin is also a huge fan of outdoor free and not-free festivals of varying size. If your lucky something fun like that might be going on. It looks like you missed Eeyore’s birthday, but keep a look out for other festivals.
When I left Austin, traffic was just getting heavy. As I understand it now, traffic is always bad, all the time, and flows in every direction. Crossing the river is the worst. When I left there were no east-west highways, only north-south. They’ve solved that somewhat now, but it’s still bad.
Places for photographs in Austin are Zilker park and the Botanical gardens located in the park. Outside of Austin, Enchanted Rock and Pedernales (pronounced Perdenales) Falls State Park are good for nature pictures. For hills and cliffs and stuff, just drive out 360 (Capital of Texas Highway) on the West part of town. It is a highway through part of the hill country, with some interesting views. Probably mostly houses and stuff now.
Oh yeah, for pronunciation. The street in South Austin, Manchaca, is pronounced “Manshack”. The street near the UT campus, known as The Drag, is Guadalupe, but it is pronounced as you would say it in English (silent e at the end). The Guadalupe River between Austin and San Antonio, is pronounced the Spanish way, with an “eh” at the end.
I’m way out of touch with the hottest restaurants in Austin, but my favorites are Artz Rib House on South Lamar (for barbecue) and Hoovers on East Manor (down home). Kerby Lane (Kerby Lane, and other locations) and Magnolia Cafe (South Congress) are great for breakfast, 24 hours a day.