Same theme but slightly off-topic so I didn't want to start a new thread. I have run a few searches but couldn't find the info for CDG airport.

I'm doing an ex-EU from CDG to SEA on an IB/AA codeshare. I will book the positioning flight with BA from LHR but I have a few questions:

1. Can I get BA to check the bags all the way through to SEA?
2. How much time do I need to connect from the BA flight to the IB/AA at CDG? I only have an 80 minute window and need to get from 2A to 2C. The CDG website suggests 60 minutes but I think that estimate is based on using the same airline.
3. Would I simply need to check in online or would I need to go landside at CDG and go back through security?

Thanks for any help.

Bob