Ok, if liteon can make a drive with +6 and -6 read offsets, why not just use 0 offsets. I mean seriously if it's always +6 or -6 it could be 0.

There older drives had a read offset of +12, and there new drive has +6. I wonder too why they can't make drives that already have offsets of zero.

The offset reference was created by Andre of EAC, after many of these drives have been in production for many years. It is just a value and by looking how various offsets match across makes you can surmise that many drives share the same 'bits' if packaged differently (even with different firmwares).

If it compares with mp3 players - which I know low level hardware of many, then there are not really that many manufacturers of mp3 players (many use others core bits) and they can be traced down family trees.

Offset is not an official requirement. The reference we use is not even aknowledged by any manufacturer, exept Plextor, indirectly, in Plextools.

I think that for the time being, it would require efforts for them to produce 0 offset drives while they don't see any advantage in return.

A factor capable of inciting them to make 0 offsetted drives would be if a drive benchmark, like CDR-Info tests, would include the read and write offset in their test results. Then they would maybe consider adjusting their offsets in order to get a better appreciation in the reviews of their product.

Yeah hopefully the cdrom and cdrw benchmark makers will incorporate offset tests into their benchmarks. Here's what I'm having a really hard time understanding though, if they can make a drive with a +6 write offset why not just shift the 6 samples in the firmware? Is this an opto-mechanical problem or a firmware problem?

Actually Nero CD Speed does report (combined) offset which is what a lot of reviewers use.
Open Nero CD Speed then go to Extra > Advanced DAE Quality Test > Create test CD.
For my Drive PLEXTOR PX-W4824A it reports:

Sorry if I didn't understand your question correctly I was just trying to give you a heads up.

I agree with the great Pio2001 more do need to vocalize this issue, with the PX-4824A being at read +98 write -30 and the Plextor Premium getting an even lower read +30 write -30 & Lite-On's ever lower Offset's I believe companies might be starting to come around. I know I'm starting to seriously consider buying a Lite-On LTR-52246S and seeing how it matches up to my several generations of Plextor's.
For the other question I will not try to answer as I am humbled before my master, Pio2001.

I don't know. I guess that the chip they use to built drives are already programmed. They must not start from zero.
Offsetting the playback would then mean to overread into lead-in or lead-out, that may introduce bugs. They could also just offset without overread, but the always null samples at the beginning or at the end would be then considered as a another bug (hey ! why cant' this drive read the whole CD ?).
As for manufacturing a 0 offsetted mechanism, I know still less about it. Maybe the test CD or workstations used to calibrate the laser can't give them the offset. Maybe they stop tuning the mechanical part as soon as they fall into the specifications, and don't go further until the offset level of accuracy. Or maybe their tuning methods are themselves offsetted and give them offset zero while we measure offset x.

Spath (CDFreaks.com moderator, optical storage technical discussion section) would maybe know.