Can an ipad4 replace the cell phone, laptop, and kindle?

I am living out of a backpack at the moment and am thinking about replacing my ancient Samsung T939 cell phone, which sucked from day 1. At first I wanted to get an Android phone, but I am having a hard time figuring out which ones are good and which ones are the new T939s. Then I thought, maybe it is easier to just buy the iphone which you know is a decent phone. Then I thought, maybe I should get a kindle so i can read some books without having to carry them around. Then I thought, what if the ipad could replace all of these and my laptop? Then I could just have ONE device to do it all. The ipad4 is 4G compatible so i could stick a micro sim card in there….

-Can it make phone calls over a cell phone network?
-Can you send text messages over a cell phone network?
-Can you edit documents and make pdfs and powerpoint presentations?
-Can you use it as an ereader, and where would you get the content from?
-Can you plug in regular keyboard and mouse?

Is there anything else I should know about what it can’t do? I am not a mac person.