I have several questions

I want Asterisk to call me with a wake-up call each morning, and when I answer that call I want it to tell me the weather.

So,
What will be the best way to implement this kind of plan?

What’s the easiest way to implement Text-To-Speech?

Is it possible to pass the audio from a command line application to my SIP channel?

I have Asterisk installed under Debian right now, installed via apt-get. Can I implement this without having to compile Asterisk manually?

Also, can I send the output of a shell script or command to a variable that can be used in my dialplan?

You may want to have a cron job that would use a call file with:
nerdvittles.com/index.php?p=160
nerdvittles.com/index.php?p=136