i think the "who is getting the guillotine?" is malicious framing. i assume u just worded it that way because it sounds funny but it still has effect of making ppl more reluctant to voice criticism.

no landlords should be killed. their private property should be transfered to a public ownership model and portions of their financial wealth should potentially be seized. ideally all housing would be made public but as a transitionary step, at least private housing should be.

for your examples, since we currently dont have good options for simply making those houses into public property, with the peopl who previosly owned them getting dibs on living there, its fair for them to keep the houses as private property for a while, without living there. letting other people live there for the meantime is also a good idea. just let them live there for free, under the condition of keeping the house livable and paying for upcomming costs. maybe offer yourself as a hireable manager for the house, if you want to get moeny out of it. why should people have to pay you for using something you dont need, if thats not reducing the value?

and yes, i am aware that being ethical with ones private property is hard, because its discouraged by current policies and public mentalities, but that doesnt mean its something we shouldnt strive for, on an individual and grander social level.