It's fortunate that Wizards of the Coast can't keep it in their metaphorical pants and keeps trying to go for all of the money in the most obnoxiously predatory ways and has done so since at least 4th edition and its attempt at a virtual tabletop monopoly and "blind bag" miniature peddling.
I need to train myself to stop saying "D&D" for tabletop fantasy games because I am not going back again. I left before, and this time it's permanent. Fuck WOTC. 
Everyone is obsessed with Mothership these days but I can't stand it personally. The whole game revolving around "your characters are going to die all the time yay!" is a strange way to run a game. It's so hard for players to get invested in roleplaying when they don't have time to learn who their character is. The system is good (because d100 is superior) and the universe is cool but as a player how am I supposed to care when I know my character isn't going to live more than a couple of sessions.
I think that's more of a warden/player choice than a system issue. According to the Warden manual, rolling should be pretty rare, as opposed to DnD where you roll for near everything. I'm sure you can lean harder into killing the players if you want, or the opposite direction, managing stakes seems to be where the real skill in a Warden comes from.
Maybe, but the fact that the top of the sheet has a score which is "number of sessions survived" and basically all the interactions the players have with the world are "try not to die", it's not really set up for a long campaign with the same characters. It certainly could be run that way though. It's just not my cup of tea.
Ey, to each their own! A lot of that comes from tone setting, and you absolutely can run it as a meat grinder if you want to. I like it because it can be easy to drop in or out of, personally, as a new GM it's nice.
Plus, I bought a sandbox module that seems to be more focused on political intrigue and revolution than outright horror, so I can swing it in another direction if I want.