Questions about freebsd-update

[Quartz]

Have a couple odd situations I need to work around. I'm wondering if 
anyone can help me answer the following questions about updating:

1) How do I get a list of available updates for a system WITHOUT 
actually downloading anything or writing any files to disk?

2) How do I get freebsd-update to install only specific patches or 
updates instead of everything?

3) How do I (or even can I) manually download patches onto a usb drive 
and then install them onto a machine that has no internet connection?