Will a herobrine mess up my iOS?

It depends on whether you want nail polish all over your fingers. It's mainly a cleanliness thing, but it's optional, really.

Since it is dark out, it will be difficult to see him, and he could sneak up on you at any moment.

Herobrine does not have a set amount of health points. It depends on what mod you download to how hard he is to kill. Sometimes, mod makers, try to keep...

It won't make any more mess than your Guinea pig already does on its own.

It depends on which mod/command you use. Usually, he just tries to kill you by summoning minions and eventually attacking you with OPed weapons.

No, but you can prank your friends by changing your skin to Herobrine.

Don't worry, it happens to everyone sometimes. Just excuse yourself, say you got it wrong and ask the customer to repeat it. Don't be nervous, just be kind.