lol no, windows are easily replaced, especially drivers side/passenger windows, so easy, few screw drivers and a haynes manual, hour job little skill required.
c/s no to the halfords touch up paints, trust me they're sh*t!!
Depends what colour car you got still
some colours like red etc can fade a 1/2 a shade every couple years so unless you have a brand new car when you open that fresh pot of red, it's not going to match up unless you do the whole car. Other colours like black and silver for example will match up aslong as you have the right colour code.