Yes -- rolling is the only option once knocked down and, although the floored opponent should be at a disadvantage, the armoured specials in MKX were a better system than adding more universal attacks that are predictable and that don't work as intended much of the time.
Yes -- MK11 is currently more throw-centric than SFV is. It's like what SFV was a couple of years ago, but, made worse by the down-1 jabs, that serve as effective "ticks" for "tick-throws".
Jumping has always been clunky in MK games, and some of the animations in '11' (like Kitana's janky floating jump) seem to exacerbate the issues. Shao Kahn's jump is pretty decent for a big guy (he's got a kind of Darkseid heavy kick), but, I do see problems for those who play against me in this department, and I heard many complaints as such.
Yes -- "death korners" in MK11 are particularly broken. Just watch any pro match, and if the floored player does not have defensive meter to roll away, it's game over. Most modern, 2-D fighters have this problem, however, and it's because most are very rush-down and mix-up heavy, the throw systems are over-powered, and the defensive systems aren't robust enough to deal with corners. MK11's meaty hits only make it worse, and also wholly reliant on ground rolls to escape death korners. I actually tend to back away from cornered opponents, because it renders it a guessing game, and one that's firmly to the non-cornered player's advantage (which feels kind of cheap).
Nah... It's just that you're at a MK fan site, and most dote on anything "Mortal Kombat". Thus, you won't get much sympathy here (even if people do agree with your sentiments); as the "echo chamber" effect and coherence theory that underpins mob rule, is strong here. I'm different because I just don;t give a shit, hate sheople that lurch along with the herd and, frankly, I just don't give a fuck what nomies think.
Your complaints seem to be mostly rooted in fact and, unfortunately, it's unlikely any of it will be addressed in any meaningful way (as is NRS's custom). In fact, I saw an MK_Tom_Brady video recently that called for nerfing the ground roll escapes (for forward rolls to use x2 meter stocks)... Which, if anything, would exacerbate some of the problems you cited -- nay mitigate them.
Just forget about it and buy the DLC ¯\(v_v)/¯