Tammy, to answer the simplest question first for now, "What does
having all my content in a package do for me?"
Per-se, not necessarily all that much. For example, you automatically
get permissions on the package instance, which may or may not be
useful to you (in the past it has been useful for me). But more
importantly, packages are the standard way to organize anything in
OpenACS, so unless you have a good reason not to, IMO you should
always put all your own custom stuff into a package. At the very
least, I've never seen putting custom stuff into a package be a
drawback, so the easier question to answer is "Why not put it
into a package?" Usually the answer is there is no reason why not, so
you might as well do it.