As fellow RTC user, here is what I've been able to figure out:

- the build log sits in the build server next to the workspace extract while the build is running. It doesn't appear to get attached to the build until the build is done (successful or otherwise). In a pinch, you can logon to the build server and manually look at the file to see where it is. But normally you shouldn't do that.
- you can break up your build into steps. Between each step (if using an Ant script) you can use the startBuildActivity task that will appear as a step in your build. For example, steps for compile, package, test, etc.
- after doing a number of successful builds, the client can show you an estimate of when the build will complete. This appears to be an average of the last few build times, so your mileage may vary.