(2) Scott Adams made an adventure interpreter was was similar but less sophisticated than the z-machine but similarly portable, in fact you could write a Scott Adams interpreter in BASIC [1] but he also wrote interpreters in assembly for the most popular platforms
https://6502disassembly.com/a2-scott-adams/interp.html
(3) Infocom developed the games on a PDP-10 machine which might be the last general purpose computer that survived with other than the 8-bit byte. (Though it had bitwise addressing which helped it cope with the industry going in that direction).
[1] Notably if you tried to write an adventure game in straight up BASIC you'd struggle. It's not like you could look up a verb in a hashtable and dispatch to subroutine. You'd be writing incredibly long if-then-else ladders nested inside if-then-else ladders which is bad enough in a civilized language.