recommend a cordless power drill

[fourtheboys96]

I am not an expert but I've been reading about tools so I'll answer your questions based on what I know (which is not expert knowledge hahaha)

1. Brand and model, with service center, spare battery, etc available here.
You can't go wrong with popular brands like Makita or Dewalt or Bosch. But the price maybe on the higher end. So you can settle on their "small brothers" Maktec or Black&Decker or Skil. I am not sure though if Maktect has cordless drill. Parts and service for these brands are available locally if I am not mistaken.

2. Just for the occassional repairs and DIY projects, so i don't need the really powerful ones.
You can't go wrong with power (torque specifically). If you have the money, go with the more powerful one. Also consider how long the battery lasts and charges.

3. Is it OK for relatively sustained operation, say mixing paint?
IMO, Mixing paint is an easy task for a cordless drill. But you might need a variable speed drill for this. Drills usually rotate very fast which is not necessary for mixing paint.

4. i noticed that Black and Decker drills tend to be cheaper than other brands; ok ba siya?
Though not cordless, my B&D drill is at least a decade old and still no problems. Used it in numerous DIY projects and some minor home repairs. I think it is made my Dewalt.

5. Does the voltage have any bearing on the power the drill has?
I have no idea. But make sure the voltage and frequency rating of the equipment matches those in your house, shop etc.

6. Will a 1/4-inch drill bit fit in a 3/8-inch drill chuck?
Yup!

7. Lastly, which brand has the most available and cheapest battery replacement?
Ask the guys in this forum PinoyHandyMan - Do-It-Yourself Community