Hops,
Lots of good advice here. I met my bf through an on-line dating service, so I am testament to its value if you are smart about it. Jona pretty much has the list of do's and don'ts the same way I did. It gave me the opportunity to date a wide variety of men (although as you get more proficient with it, I found you weed them out faster and go on less dates), see a broad spectrum of personality types and determine what was really important in a potential partner. I did insist on their paying in the beginning (and most of them didn't go beyond one date), but if the relationship lasted for awhile, I began to pay periodically.
Dating at our age, with perhaps teen-age and young adult children in the picture (my bf and I have six of them between the ages of 16 and 23), aging parents, perhaps grandchildren, retirement looming, etc., creates many challenges that we would not have had in our 20's and 30's. Rather than talking about whether or not you want to have children, career goals, buying a home, saving for educations and retirement; it becomes about when do you think you can retire and where would you like to be living when that happens, is there enough money to support us as we age and need more medical intervention, how do we protect our individual children upon our deaths if we were to get married, and would you love my children and grandchildren as your own. Both my bf and I love our children very much and would like to be able to be close to them geographically, but know this won't always be possible or practical with so many to consider. We also value our independence from them and being able to not be reliant on their help or financial assistance as we age.
With all that in mind, if the chemistry is there, the next thing needs to be flexability and the ability to compromise. We all have accumulated a fair amount of baggage by now and being able to work with that (or not) is the determining factor as to whether the relationship can have legs. I do not believe that we should be the ones doing all the compromising either. It must be a two-way street with a willingness by both parties to meet half-way. You also must be willing to walk away if you reach an impasse on any totally objectionable habit. No, they will not change unless they want to and don't ever plan on that happening.
I'm not sure if I answered your original question, but maybe there is something there that you can use.
Hugs,
Brigid