Yes, bikes tend to have shorter service intervals than other vehicles because the engines tend to have a much higher relative performance. They also have smaller oil reservoirs because of centre-of-gravity issues. It all depends on the bike. 600 miles for the first service and 3,000 miles is typical. The services aren't usually all the same, there will often be alternately and expensive one and ... an even more expensive one.
You need to get into the habit of taking control of your bit of road. This isn't something I tell anyone without worrying a bit about it. We're not talking about being aggressive, we're talking about giving information by means of the way you ride, and in particular with your road positioning. The other driver in this case might easily have mistaken your left-of-centre position for an invitation. On the other hand he might well have seen an inexperienced rider and decided to take advantage. You can learn quite a lot about the human race when you start to read the way they drive. If you're staying well over to the left and then you find yourself in a tight spot, you might have nowhere to go but over the kerb, or even nowhere to go at all.
When I have a piece of road I try to let people around me know that it's mine for the time being and that I'm confident of managing the situation. Then they know that if they want the bit of road I'm using they will need to wait until it's free. Rarely, they will want to take it by force. Unfortunately, as you've now discovered, it happens more often than you'd think -- especially in dense traffic at rush hour. In that case I'll go somewhere else, my safety comes first. That means I'm always on the lookout for another safe haven just in case. If there isn't one I'll often make one. Sometimes I'll use one driver to protect me from another. You won't be able to do a lot of this stuff until you're both completely at ease controlling the bike, and able quickly to size up the situation that you're in at that instant and plan your response to it. It has to be said that it helps a lot in planning and execution if you can call on way more power than you could at present safely apply to your back wheel. That's unfortunate in some ways but the simple fact is that you can accelerate into trouble a lot more easily than you can accelerate out of it.
As I said, I'm a bit nervous about this. Broadcasting information to other road users through your riding, controlling the road and the traffic around you (yes, you can to a degree control the traffic around you), and keeping three or four bolt holes handy just in case are advanced techniques and you don't want to forget about the run of the mill stuff while trying to do something that you're not yet ready for. For the time being you're obviously learning fast and you seem to be getting along OK so please don't try anything too fancy. Watch what's going on around you as carefully as you can and learn from it. Stay cool. Remember that for most people, once they've passed their test, driving is just a way of avoiding the walk and they have no incentive to want to do it any better than they do it now -- which by and large is rather badly. Most of them don't even know what their tyre pressures should be.
Oh, and your horn is "to let others know you are there". If you think you're going to need to use it, use it sooner rather than later. Try to get into the habit of making it sound like "Have you seen me?" rather than "B@$T@RD!"
