I've been an owner of a modern urban roleplay sim since June 2017 and I will say that sim ownership is difficult and carries unique experiences that no one can prepare you for. People will try to push and change your sim to suit their needs, it just happens. I think it's good not to be a stick in the mud and try to leave room to be flexible, however it's important for sim owners to stay true to their vision and remain stable. Consider if a player asks for a change would you be willing to grant something like it to any other player which may ask you to change it? It's very important to also keep the community active with LOTS of opportunities which are pushed frequently in roleplay and group notices, otherwise stagnancy sets in. Personal ground rules are extremely important as well as constantly enforcing the standards of the sim with staff and players alike but in the same token not being TOO over reactive and for god sake be a decent human being even if you pay the tier, encourage your staff and players to be decent too.
Owning a sim is a lot of work and that player who one day purchases a full region will have difficulty if they're making a sim if they're looking to be a 'sl aristocrat' or try to wield any type of power or be too overly aggressive to players while being too lenient for others, that is how you end up with a sim that only has the owner's friends on it and nobody else. Mainly hosting a RP community is all about being welcoming, advertising, encouraging RP and events, and as owner be the player you want your players to be- lead by example, be creatively open to new ideas, creative in your build, provide areas to convene in RP that anyone can walk up to and start. Realize that yes it is indeed a financial commitment but to make sure you have varied rentals people will actually be interested in with an environment that actually feels a place one may want to live that suits their characters. Players feeling at home and 'settled' is very important for many but never depend on their rental income.
Another important aspect to consider, as sim owner your sim will have ups and downs, traffic ebbs and flows but it's your responsibility to advertise no matter what the traffic is and for the love of pete do not immediately close if the traffic ebbs, you should be expecting it already and it will be back if you put the effort in, seeing sims closing all the time is very disheartening to those players affected and I have heard many people say they lost their drive to roleplay in general due to it. If you don't advertise often, don't hold and encourage events, don't roleplay with other players daily, or do anything to draw people to come and visit you may as well not have a sim at all, as owner don't waste your time if you don't plan on doing all of that yourself. What you do as sim owner is a labor of love, period.
Those are my 2 cents!