Since the above posting in April, I have finished replacing the valve cover gasket, the oil filter housing gasket, the CCV valve and hoses, the oil level sensor, the forward O2 sensors (pre-cat converter), the air filter, cabin filter, throttle body gasket, rebuilt the disa valve and changed the oil and filter. Most things went well, although they always took longer than expected. I found information on this forum to be very helpful, but with one caveat, which is that information is often presented as though all e46s are the same and that is definitely not true. I found significant differences in several instances between my 2003 325ci and what had been posted for a generic e46.
One case was for replacement of the CCV valve and hoses. Although it is good to do that at the same time you replace the OFH gasket, that alone will not be enough for you to have the necessary access. On my car, you will also have to remove the disa valve and throttle body in order to get to the screws that hold it in place as well as to be able to route and seat the hoses onto the CCV so you get a solid 'click' and tight connection. As far as replacing the hoses is concerned, IMO that is a no-brainer. I found my hoses to be very hard and brittle to the point it would have been ridiculous to try to save money on hose replacement.
Also, in order to replace the oil level sensor, you will have to work a lot harder on my year model than you apparently do on earlier models where the sensor was pictured to be out in the open in the forward part of the oil pan. In my case there was a large, thich, heavy aluminum plate that covered the oilpan and sensor that was held on with 8, 17mm bolts and the sensor was at the rear of the pan on the driver's side. Since I was working alone in my garage with a jack and jack-stands, it was pretty difficult to get that plate out of the way enough to have access to the oil level sensor. I left one loosened bolt holding it in place so I could rotate it out of the way because I knew it would be a bear to get it back in place and get a bolt started while trying to hold it in place with one hand. Then, after I had finished replacing the sensor, I re-tightened the loose bolt and guided the plate so it would line up with the other holes and then added a couple more of the bolts across the front of the plate. I would highly advise anyone working under those same conditions to either do the same thing or have someone help you. On the plus side, removing the alternator so I could get access to the OFH was a piece of cake compared to what some other people said they had to do, so that went pretty smoothlly.
If anyone with a 325 close to the same year as mine is about to tackle any of these jobs and would like more information, feel free to contact me and I can go into more detail if needed.