Expert server controllers will only change the runways in use if current conditions call for it. Winds can be disregarded under 10 knots, as a 5 knot tailwind or crosswind really doesn’t do anyone any harm.
When planning your flight, I’d suggest using weather forecasting tools to determine which runways will be in use when you arrive. A great website that I use is windy.com. At the bottom of your screen, you can slide the timeline to the point at which you’re expected to land.
Another method, as Danny mentioned above, is to choose a STAR that applies to all runways. That way, the only thing you have to do is change your approach.
Regarding multiple directions in use, that probably shouldn’t be happening at controlled airports. Feel free to shoot your controller a message if you ever have any concerns. To find your controller on the community forum, you can use the IFATC Directory.
If this is happening at uncontrolled airports, just go with the flow – do what the majority is doing, even if you disagree.
On the live servers, winds are in real-time, based on what is happening in the world currently. If both runways are green, this just means that both runways are okay to use.
Note that runway colors don’t determine active runways; they only indicate wind in relation to the runway heading.
Green = Headwind, desirable
Orange = Crosswind, less desirable
Red = Tailwind, not desirable