I really have no idea what the sensor architecture is, but the distribution of masked sensels won't be anything like the layout on a reflex DSLR CMOS, it's probably closer to that of a phone camera sensor with the same inherent problems... Small...
No.
This is normal as they age Best to use them up in a couple years really. It all depends on how you care for them!
Its been a few years for Your battery it's acting its age. You will need to replace it in a while. do it yourself its very...