Can you press A to swiftly go to the parent dir and B to go to the previous dir in history (and C for the next), and D to switch to the next tab?

Alt+up arrow gets you to the parent directory. Alt+left arrow gets you to the previous folder in the history. Ctrl+tab gets you to the next tab, or ctrl+[number] to go directly to a specific tab.

How is Alt-up, which requires holding a modifier and moving your hand off home row, a SWIFT alternative?

If it's not for you its not for you, but pretending that a keyboard shortcut of alt plus a key is somehow an entirely different concept and outside the realm of alternative is pretty hilarious.

I've capitalized that word specifically for you, but yes, if ignore speed, then bad keybinds are in the same realm.

Likewise, having a single E key to jump down by 10 items in your realm would be no different than pressing the down arrow 10 times , or using search to find the file which ends with "_abc" is no different than using your eyes to find all such files and then using a cursor to nagivate to them and select - after all, these are all keyboard-only (except for the find part)!

lol, I just figured out I'm being trolled. It was subtle at first, but you went a little over the top with the comic book guy style 'well akshully' stuff at the end that let me suss it out, but you really did have me going for a while. Kudos.

Beats the hell out of using the mouse, which is what my colleagues do.

I'm not much one for home row. I'm an evolved hunt-n-peck, as typing programmes made my fingers hurt. Works for me, and in an office of secretaries, I'm one of the fastest typists.

Backspace is sufficient to go to the previous.

Sorta? Alt-uparrow navigates to the parent directory. (Also, Alt-left/right arrow will move back and forth through your folder history.) Ctrl-Tab/Ctrl-Shift-Tab will switch among next/previous tabs.