Whoa sorry to hear that, I doubt you can program any button like that with a standard IOS software, maybe on the jailbreak community there is something but I don't know. However, this can help you if you trying to get the home button functionality Assistive Touch
Your earpiece speaker might had gotten shifted during the battery replacement. Make sure its two contacts are touching where they are suppose to be. The earpiece speaker is located on the front screen. Here is the guide to it.
Hi, does iTunes recognized it if connected? If so, try a hard reset on the phone by holding the power and home button for around 12 secs. If that doesn't work the screen might had gone bad, or the lcd connectors could have become loose if the phone took a fall. Jose
Hi, if your cable is not plugged in properly your digitizer will not work. I would say remove it and make sure it snaps into place properly. The 3G and 3GS plugs are definitely different so when you remove it do a side by side comparison with the old one you remove from your phone. They should be identical and the problem will hopefully be solved by plugging it in correctly, if they are different most likely you received the wrong part aka 3GS. In which case email iFixit so they can send you the correct part. Jose
Hi Kevin, I know for a fact that there are some rear replacement cameras for the iPhones that are manufactured without the autofocus. As all of these replacement parts are grey market parts some of then are really cheap quality and some are good quality. It sounds like you got one of the cheap ones that do not have auto focus which is weird since you said you got it from iFixit and usually their replacement parts are good. If I was you I would send iFixit and email and ask them to send you a camera with autofocus, if not luck, then search for another vendor and make sure to ask them about it before going forward with spending your money on it. Jose