Horn of the phantom beast?

3 simple situations (i edited a 3rd):

1. My monster equipped with horn attacks another with the same attack points, do I draw?

I imagine it's a yes cuz the equip card goes to grave after both monsters go to grave first.

2. My monster equipped with horn attacks ryko, do i draw?

Here I think it's a no because Ryko is still on the field when both the equipped monster and it's equipped trap card go to the grave.

3. If my monster has horn and my opponent controls it and destroys another monster of mine, who gets the draw? I say me cuz that's similar to Armory Arm's effect.

I'm not sure about my answers (otherwise i wouldn't ask), so thanks in advance.

In both cases it's a no, just like Goyo Guardian, Guardian Joan and Blackwing - Shura the Blue Flame. The card needs to stay face-up on the field until the monster is sent to the graveyard. In the 2nd case it's pretty simple to see why it would not activate. In the 1st case though, the card goes to the graveyard at the same time with the monster, so it would not activate.

I'm Pretty Sure That Ryko Goes To Gy Before Its Eff Activates But Its Like During Damage Calc So Still Wont Activate.

You are wrong Rand. Ryko still stays on the field. Ryko's effect activates in substep 6 of the Damage Step, while he gets sent to the graveyard in substep 7 of the Damage Step. It's the reason he is negated by Skill Drain.

For the second question yes.

^Your statement is incorrect.

by HoTPB's text it's obvious that it's effect activate at the "End of Damage Step".
Since the monster equiped is destroyed at "Damage Result" and simultaneously HoTPB is also destroyed.
at the "End of Damage Step", HoTPB won't activate it's effect.

For the 1st question, A monster is considered to be destroyed by battle "After Damage Calculation", and a destroyed monster can't be targeted including equip-card. As such, it's not the equiped monster who destroy a monster by battle and send it to graveyard. HoTPB won't activate again.

3. None: your monster isn't destroying any opponent's monster.