1) - our main fuse (before consumer unit) is 60A. Is this OK in a
household
with a 10Kw shower ... no other really big appliances ... 13A rated oven,
kettle ...

Should be OK, provided you don't run all the laundry at the same time and
don't use electric heating of any kind. It is a bit marginal, though. With
an electric shower, a 100A cutout would be nicer.

2) Every time an incandescant bulb blows, the MCB trips
a) is this normal ? If yes :

Yes. As an alternative to the other suggestions, you could fit energy saving
compact fluorescent bulbs. These last ten times as long and don't trip the
MCB when (should that be if?) they blow. They also use about a fifth of the
energy and don't lead to needless pollution of the atmosphere with carbon
dioxide causing global warming.

Christian.