1st, don't treat your production environment as a sandbox for testing. You should find another box(es) to test your software on before you deploy to production. Ideally your testing boxes should be similar to your production boxes. And, if possible, isolated from the production network.
Another option is to use a virtual network with servers and clients to test the software on existing hardware without interfering with the physical network.
answers to your questions
1. it's testing so preformance isn't the top concern, although load testing should be done at this point. I would deploy a release build. Hopefully the application includes some logging, so you can enable logging if things aren't working quite right to determine what the problem is. If your not, then i recommend a logging library like log4net.
2. you can't. However if you built a typical webforms based website you will likely not crash the server, only the web application. To prevent bugs I recommend a testing framework like nunit or mbunit. they allow you to test pieces of your code in an automated fashion. then when you tie all the pieces together they should work without error.
along unit tests you can test the complete application in a virtual environment. see my starting comment.
3. Again I strongly recommend not deploying from your development machine to production. There are too many variables between the 2 environments for things to just work. Deploy to the intermediate server for acceptance testing and make sure everything is working properly. once this is confirmed, then deploy to the production server.
Jason Meckley
Programmer
Specialty Bakers, Inc.