Been having some electrical problems as of late.

The 'high beam on' indicator light that sits on the dash seems to come on and off intermittently. I later realised that it happens when you move the indicator/light switch around, something seems to be broken or loose or broken inside. Anyone had this problem before? Not really sure what its called but im assuming that the whole switcher section will need to be replaced, as it would be too fidly to fix whatever the problem is inside the unit. If thats the case, how difficult would it be to replace?
Also be having problems with my alarm, but thats another story, still covered by warranty.
My main concern is that my battery is dead, and more so then not requires a jump start from my protable jumpstarter. I want to replaced the battery but dont know if any of the problems that i am having are draining it. If that was the case, could this cause damage to my new battery, or significantly reduce its life? I really want to get a new battery, but dont untill i have fixed all the electrical problems, however its a pain driving around with a battery that is on its way out, so i would prefer to get one as soon as possible.
Thanks in advance for any help.