There is no difference in maintaining an o-ring or x-ring chain, they are both the same principle it's just that the x-ring is cut differently. All chains have a master link, whether it's a clip or rivet and they all need to be cleaned and lubed. Although o-ring chains have sealed lubrication for the bushings, they still need lubrication between the bushings and the rollers.
I clean the chain by warming it up with a 5 minute ride, spraying some wd-40 on a towel and rubbing all the crap off the chain. I then wipe it clean with a cloth and then I spray some chain wax on to help keep it clean. Let it stand for about 15-20 minutes and it won't fling. Never use a brush to clean an o-ring chain as you may damage the rings. I've never had any problems with wd-40 but with my new 520 conversion, the o-rings are more exposed so I think I will switch over to kerosene for future cleaning.
I definitely recommend using a rivet link rather than the standard clip type. You can get a chain kit for well under $100 if you shop around on-line, and it will be worth it the first time you use it. Check with your local dealer to see how much they charge to replace a chain and you won't need any more convincing to do it yourself.
I get about 10,000 - 12,000 miles out of a 525/530 chain. Not sure how long this 520 chain will last. I'll just have to wait and see.
Also, I've never worred about how straight the tire is. I do use the markers on the adjusters and have never had a problem.