No, there are no errors during boot.
Here you are more details:
init: ureadahead-other main process (349) terminated with status 4
This line means that the process
ureadahead has finished doing its job and has quit.
ureadahead is a program that is run to speed up the boot and the exit status 4 is perfectly legitimate (see also
man ureadahead and
udevd: BUS= will be removed in a future udev version, ...
This is a deprecation warning:
udev will change its programming interface (API) a bit in a future release. This is something that the developers will have to work on, but nothing that prevents the system from working properly.
udevd: can not read '/etc/udev/rules.d/z80_user.rules'
udevd is looking for a file that does not exist. It's perfectly OK if you do not have this file: you need it only if you want to customize udev.
fsck from ... /dev/loop0: clean, ...
fsck is a tool that checks your filesystem for errors. "Clean" means that everything is OK.
The last two lines are just notifications that Apparmor and Sensor Limits are being started.
From your logs, I see that you are running from a CD or some device like that. CD performance are suboptimal, so probably you are seeing the messages because the services are started before the splash screen is shown.
Anyhow, everything is working as expected and you shouldn't worry. I hope to have solved all your doubts :-)