B is an unusual concept and I didn't detail it very well. I'm thinking of the neoclassical bedroom sequence where he sees older and older versions of himself.
The core of that story would be that the man refuses to die until he has some taste of the future that was promised to him as a child -- the future where space travel is common and we all wear skin tight spandex clothing while the Blue Danube Waltz plays. I would play with his states of consciousness and have the beeps and gear of the facility transform into or trigger him imagining 2001. The monolith could be just him holding up a smartphone, black and shiny because it is turned off, against the room in that position. For IP (copyright) concerns I would have to avoid crossing the line and make sure that it is clear that this is about how 2001 and similar 1960s space propaganda set unrealistic expectations for all of us.
The POV gets more surreal as he approaches death so that by the time he is approaching the billionaire's rocket we suspect that this is just his detachment from reality but leave it open to interpretation about how far he really got.
Mostly I see that story as an exploration of 'What happened to the future we were promised?' Technology was going to end hunger and war but somehow we got to today where technology is so useless and obscure that, for example, no one can fix a brand new car.
F would be tough to cast. I like that it could be shot mostly in one location. The frog man is interesting because Chaplin thought of himself as deformed and exaggerated his proportions by wearing giant shoes, etc. 'The X-Files' did an episode loosely based on the "frog man".