Welcome to the forum.

You do not need a task killer.
If you search, you'll find a lot of information here about task killers.
But long story short, your phones os is designed to manage it's own memory.
Killing tasks is only going to cause them to start back up, using up more resources than just leaving them alone.

 

No you made a good choice, knock offs don't work well I know from experience. I own the Seidio and love it

 

Task killers, are indeed bad. However, something like system panel that shows CPU usage, memory used, etc, is good because you can find out with hard evidence what's causing problems, rather then mindlessly killing everything thinking that your problem is now gone.

 

I shall reiterate the lack of need for real killers. There are very few instances where they are useful, but having one around is jit a bad thing...just don't go around killing apps solely to free up resources.

Regarding batteries, I got a couple of cheap batteries that seem to work just fine in my phone. Check reviews and adhere to the general rule of thumb that if thet are cheap, they are probably crap. YMMV.

 

Seidio is the way to go.

I bought a battery off of ebay, and they only last a few hours.
They are good if you just need a spare to carry in your pocket to get you thorugh when your battery dies.
But definately not as your main battery.

 

From what I've read you shouldn't do that during the first, say, 3 charges. After that I don't think it's a big deal.

 

The consensus is that android is keeping those apps in an idle state until you call on them again. For the most part they will use very minimal battery though you will occassionally find a rouge app. Handle that issue when it occurs. Check into apps like system panle...juice plotted...spare parts. All in the market. Find and read the task killers why you shouldn't use them thread.
Several of us have found task killers do more harm than good and some use them with no reported issues. The main issue I have run into is improperly set up task killers. If set up wrong they can kill needed background processes and apps needed to run properly.

 

For your reading pleasure.......This should help you to clear up why you don't want to use one.

This has been discussed to the end of the earth!!! If you don't want apps running then root your phone and remove them. If they are third party apps then un-install them. But read the articles in that link and then decide but remember this is not windows.