A few php Phar questions

A few php Phar questions

A few questions but I'm sure the answers will be useful for many getting
to grips with the relatively new phar.
Is it possible to delete or edit a file inside the phar script, from
within the phar script, when it's actually running?
I've noticed that I can change the name of my phar file from
examplename.phar to examplename.php and run it in the url and it still
works fine. is that right? is that OK to do? is that safe?
Is it better practice to put all your files in the same directory and then
phar it, or is it OK to keep all your folders and sub folders and phar it
like that - or does it not matter?
can you obfuscate the phar file. or will that ruin it? does all
obfuscating have to be done before pharing?
Hopefully a phar expert can answer these. thanks