Credentials for push install of new clients.

This is a two part question, basic stuff....

1. When adding multiple clients at once, it will ask me for my credentials for each individual client.  Is there a way to enter the credentials only once or is that just the way DP works?
2. I am using my own admin account to push the client disk agent.  Are my credentials being recorded on the client?  When I have to change my password, is the backup for any client I pushed going to fail?  Or are my credentials only used for the install and that’s the only time they are referenced?

Thanks in advance,
Randy