I live in a hard water area, and the house I just bought seems to have a
lot of problems with it's basic water plumbing, mainly steming from
limescale.

Questions:-
1) Would a water softener help reduce the limescale build up over time,
without replacing all the pipework?
2) What types of softener are there, and what are the maintenance costs?
Which ones are effective ?
3) How easy are they to fit diy?
4) Any other considerations I need to think about before spending my dosh?

(the house is 6 yrs old, 3 bed semi, 2 bathrooms)