Well, it depends. There is no obliged way to play bass, only different methods with different priorities. If you're getting a teacher I would suggest just buying a new, standard, set of strings and tuning it standard, as I would think not many teachers would like to teach a beginner with a BEAD bass. However, bass playing is about fun so if you like it like that, then keep it that way! Also, if you're playing in a metal band then going that low is a pretty desired feature, so I would keep it that way. In reality, even if you played standard music, the truth is that there's always more use for a B than a G on a bass, in any type of music.
So in the end, it is really up to you. Heck, if you do get a teacher there might be some that will be ok with this! But again, only do whatever makes you have the most fun.
P.S. To answer one part of your question that I did not address: Amount, or types, of strings are not what decides wether an instrument is hard to play or not. It will be the same as hard as playing any other bass. The only difference might be that you may feel your fingers hurt more on a B than a E, but it's because you're just a beginner, and your fingers aren't used to it, and it will hurt a bit anyway no matter what type of string you play.