Single software Android

[parth.gohil]

i am new to android development and i need to know a few things.
first.
can we tweak android so that it runs only one application so that after boot only one application launches automatically?
also can we disable file transfer or protect the files put on that device ?
can we connect an android device to a printer ?

if these questions are answered i can figure out if the concept i have in my mind is feasible or not.

Thanks.