Job done, I tested by extracting a virgin root64.gz, then I "remaster" it with both modifications/simplifications (which I proposed), and cold re-booted fresh (base + norestore). ALL is OK.I check them (with cat /etc/inittab, cat /sbin/autologin) to see that the modifications are really in place.Then from (already logged tc user) I "exit", and at login prompt I put tc, and voila: I am back logged.
PS: I used a laptop (so tty1 was not a problem) with AMD64 cpu. But should work on any cpu (I did not tested for arm, pi-core etc).
PS2: The changes are pure theoretically/didactically, because no speed gain. But I like CLEAR, only necessary shell commands./scripts.
I do not take any pride, neither affront, if these are not interesting for tc users. Each on their way.
Regards, and thanks for Tinycore free software.