lagering without airlock using plastic

Hi all, quick question:

1) Can I lager a ****tion of my brew for a few weeks in a plastic
container (say 10L) sealed loosely with its lid (allowing CO2 out),
without an airlock? I plan to secondary ferment, then transfer to two
conveniently shaped plastic vessels for lagering in the fridge. I'm
not planning a long term lagering period, only maybe 2 weeks (for an
altbier).

2) Can lagering occur at the same time as bottle carbonation /
conditioning ? I.e. can I bottle then put them in the fridge for a few
weeks? Or does it need to occur in a greater volume ?

Cheers!