i think what you're asking for depends more on the airline itself than the airline alliance.

eg: Air Canada (*A) will not through-check your luggage to another carrier if you purchase separate tickets regardless of their interline agreements.

If the oneworld carrier you are referring to is AA, then I believe that yes, they will through-check your luggage. And it will all be on the same bagtag.

As for the connecting boarding pass, they *may* be able to issue it, you'll only know when you check-in. The agent can enter your connection into their system, and the system will send a request to the other airline's system to check you in, but there's no guarantee that it works.

The only thing you should be aware of is that should there be any delay/cancellation for whatever reason on your first flight, the oneworld carrier is only responsible to get you to the final destination shown on your first ticket... and not necessarily in time for your connection.