No, you never have to kill any apps running on the Droid. The Droid is designed to close down any apps that need to be closed.
They crashed because they were poorly written or had a bad interaction with another app running in the background.
Background apps do services in the background of Chrome. They help running some scripts on the page of Chrome.
Open the first app. Touch the "Home" icon at the bottom of the Droid. Navigate to and open the 2nd app. To switch between the two apps, use the "Home" icon, NOT the "Back" icon, which will close your app.
I don't think a theme alone would slow down the Droid, but the apps you have running along with the theme may cause it to slow down.
No.
Yes, The Droid 2 has apps. It comes with a few. You can download lots and lots of free ones in Android Market (one of the apps it comes with)
A iphone is a droid it has the same internet email apps and more.
Usually, the reason an Iphone has a low charge all the time is because apps are running in the background, even though you think you might have closed them. To close them press the button below the screen twice and then hold on the apps until they shake, then close them.
Yes, you can. There are literally thousands of both free and non-free apps available in the Market which is easy to link to on your Droid.
Droid. Droid is the fastest growing OS. Plenty apps and updates. Since the Motorola Atrix launch, Droid became the leader.
I do believe you have to have a debit/credit card on file seeing how they cant bill you and when i had a droid and bought apps they took the money from my debit card. (source: Droid owner)
You need a credit card or a debit card to pay for apps.