System Can't Get Past Black DOS Window bco Bad Floppy Drive?

Just troubleshot a family member's PC. ASUS mobo (so now we're
on-topic....)

They reported periodic system freezups (supported by many, many
Event log entries). They also reported that it took them 5-6
tried to get the thing to boot (pulling the AC power plug between
tries).

I noticed it was making a lot of noise, opened it up, saw that
the cooling fins on the CPU heat sink were totally clogged with
dust so the fan was blowing on a flat surface instead of through
the fins.

Cleaned it out, went for a re-boot, but the thing kept hanging at
the DOS-like stage where it says "Press F2 for (BIOS) setup". I'd
press F2 and it would acknowledge "Entering Setup", but hang
there - same as the user reported.

To make a long story short, I wound up yanking the floppy drive
and the problem went away - or, at least, it's booted with no
problems over a dozen times since.

My guess: multiple problems.

- The system freezes were caused by an overheated CPU, supported
by the user's report that it got worse with use and was
mitigated by leaving the PC in standby mode for a few hours.

- The boot issue was caused by the floppy drive. System was
taking some sort of inventory of devices and, when it got
to the bad drive just hung there.

Does this hold up to scrutiny by somebody who actually knows
something?

My main problem is the intermittent nature of the startup issue.
Didn't observe it myself, but I believe the user. How could the
floppy drive be bad 5 out of six times, but be OK that one time?