Good idea to commute with a road bike and keep it outside? So I finally want to upgrade from my 1980 Schwinn World Sport 10-speed with suicide shifters to something more modern. 

I will be working in Texas this summer and want to commute to work, but I highly doubt that the office has a place indoors to keep my bike.

Is it bad to spend $800 to $1000 on a new road bike if it will be left outside 9-6 everyday? I will have a backpack so a tarp is possible.
Forget the tarp. Ultimately, the greatest danger to your bike is not the weather, it's thieves. As long as you invest in a good lock, practice good locking technique, and don't live in an area full of degenerates you should be fine.

My bike is worth more than $1000 and I ride it all over and lock it up outside frequently. 

When you select your bike, don't get the flashiest, most decal laden option available. Get a low-key, plain looking bike. Especially good if it has stickers and dings in it. Ideally, your bike will be the worst looking bike on the rack, let other people's bikes be the targets for thieves.

Here is a picture of my primary bike, which I've used to commute and go to the bars and get groceries etc (though I don't have the rack in the picture). I have a fairly fancier appearing wheelset on this bike, yet I've left it locked up in fairly dodgy places, but I still have it.

See this question for additional information regarding bike security: Theft deterrents (in addition to locking up a bike)