To set a breakpoint in another file, view some source in that file and then set the breakpoint. In your specific example, an easy way to do that would be:

l package2::function2
b 100
[download]

I often use x "@_" to get a summary of arguments without having to worry about some huge data structure being dumped.

You can turn down the default "die reporting level" so that dieing, for whatever reason, doens't spew so much text: "O die=0". You might also want to turn down the warning reporting level: "O warn=0".