for the time being, you are correct. CD-based nostalgia/collectibility (they are not the same thing, but in this context there's significant overlap) is not as high as cartridge-based, but it is on the rise. I expect in the next 4-5 years it will definitely start to become noticable. You can already see the beginnings of it with music CD collectors popping up more frequently than in years past.
for the most part, yes. It is definitely something discussed by current game makers. The first goal is compatibility with original hardware, but the followup 100% includes clone consoles.
i am also a retro gamer/collector. My NES (toploader), SNES, and Genesis/32X all stayed hooked up to my old CRT TV. The Atari 2600 isn't hooked up anymore (i unhooked it a couple years ago when i had to get said TV fixed). At this point, i'm not even sure that it works- it's been pretty touchy the last decade or so and it saw minimal use even before that. For those keeping score at home, my n64 stays hooked up, but it is on my flatscreen. It is the first system i bought with my own money, and it just feels wrong to think of it as "retro" for that reason, despite being DAMN NEAR 30 YEARS OLD.