Re: What are the astronauts doing?
Being mildly serious, they are dealing with most of the routine cleaning and maintenance issues leaving more time for the regular crew to run the various experiments on the station. Crews on the usual 6 month stint get training on the experiments that are expected to be running during their stay while crews supposedly on short visits only get the standard station training, so it makes sense to release the specialists from fans and filters duties. Apparently it takes about 2.5 full time crew equivalent to keep the place running.
Reported elsewhere, it looks like the thruster problems only occur when they're in a cluster. Test a single thruster in isolation and it's fine, put them in a group like they are on Starliner and heat leakage from a firing thruster affetcs the others in the group. Boeing simulated the clusters rather than test fire an actual physical set...