It's not about engine wear caused by short journeys.
Repeated short journeys, where the engine doesn't get to full temperature, can cause a build up of condensation in the crankcase, which will eventually mix with the oil.
Water in the oil isn't good.
On cars that ONLY do very short journeys when you look on the oil filler cap you can often see that capachino froth that can be mistaken for a leaking head gasket, but it's the oil/condensation mix.
Obviously if the oil it comprised with water, that can lead to wear. Hence the 'short journeys can damage engines' theory.
However, a few short journeys in the week should be fine as long as it either gets up to full operating temperature, or at the weekend you take it for a good blast.
Getting the oil temp above 100C for a while will help boil off any condensation that has built up in the week.
Regarding MC clutch wear, it appears to be stop start traffic or lots of hill starts that wears them quickly. It's not gear changes, as that is a quick release and re-engagement of the clutch, it's slipping the clutch that does it as per pulling away. I normally drop into first when going slow or approaching a junction as the clutch stays engaged more. Leaving it in second, you can hear it slipping loads as you pull away. Slow creeping traffic is another killer, as its slipping quite a lot.
You can hear it, so just drive round it by selecting a lower gear if need be or push the throttle a bit harder to force the engagement.
Saying all that, just get one.... And a enjoy it!
Don't let everything worry you or it'll spoil the experience. Maintain it well and it will look after you.
