a) I've been wearing mine for sports and pretty much every day for about 1 year. It has 1-2 small scratches but otherwise tip top.
b) I wear the Comply rubber parts, these are included (however, they break after a certain time, can be ordered new at Digitec). With these, the In Ears never fall out.
c) The sound quality is very good, the bass is also good.

So far not the slightest problems regarding longevity (but I've only had them for 3 months).
They are not suitable for very small ears. Otherwise very good plugs (not only rubber but also gel).
Bass and general sound is one of the highlights.

Somewhat negative:
Operation is sometimes a bit fiddly and doesn't always work straight away.
They are really not suitable for making phone calls outside.