1) The commander does the landings, but Role reversal is encouraged so sometimes the 'commander' will be the Co-pilot operating as PICUS (Pilot flying in command under supervision). This means that the co-pilot pretends he is in command and accomplishes the tasks that go with that including choosing fule load, take-off, land, etc. Captain retains overall command and has to sign all the legal stuff, loadsheet, tech log. With two crew the landings are usually shared.
2) Depends - Flying hour payments depend on time in the company and other allowances depend on where you go and for how long.
Any the wiser?