the boot light problem could be a pin switch that wants replacing or the wire has come of the switch and just wants pushing back on as for the central locking could be a faulty central locking motor or a bad earth on the car causing the fuse to blow as for the battery keep going flat could want a new battery or even a alternator but have this check out by either a garage or at a motor factors and they will be able to tell you which is at fault and you can then gat a replacement for it at the same time if it is he battery then they will be replace it for you hope this helps
