I PROMISE MY BETTA IS PEACEFUL he must be a rare exception
and I promise you that you simply can not know this, especially after owning him for such a short amount of time.
As others have taken the time to try and explain...
it's genetics, it's in the fishes physical make up to be a certain way.
As conscientious pet owner we take all things into consideration and do what we know to be best for them...otherwise we are being irresponsible and unfair to the pet.
If you know you shouldn't feed chocolate to your dog, you don't do it...correct?
Just as you know you shouldn't keep a male beta with anything else, therefor don't...
if you want that fish to not just survive but thrive.
that is a java fern should i glue it to the lava rock?
As for your plants with rhizomes ... make sure the rhizome is out of the substrate otherwise it will rot and the plant will die. Yes you can glue (make sure it's aquarium safe) or tie...I tie the plant to a rock or wood.
I attached a pic where you can see that I have some to the right ...one tied to a rock and the other to wood. I had to go in and do some trimming so I'd used a few newly propagated pieces.