Bjorkas in the arena

Bjorkas tries the weight and balance of the rods. "Am still sore from fight with rock man, and weapons still outside. I am lift gate, guards maybe not"

Loraatis pulls out ten of her health potions and offers them to the minotaur. Here, drink up.

Bjorkas drinks 10 health potions healing 50 hp. "Ready."

Alright, give me a moment. Loraatis walks up to the gate and looks out into the arena.

Spot Check: +8

The member 'Loraatis Pegason' has done the following action : Outcome

'D20' : 12

you see 5 royal dwarven guards still searching for someone.

Loraatis turns to Bjorkas. There are five royal guards waiting in the arena. I recommend we wait until the magical door opens, and then make a run for it. Any dwarves that follow us through will not be a threat to what is waiting on the other side.

Disappointed, Bjorkas waits patiently for the magic door to open. He secretly hopes that the little human will mess it up and open it into a meat shop.

The door opens and the royal guards stand around it and look with astonishment.

Seeing the dimensional door open, Loraatis calls to the minotaur. The door is open; now we need to get to it. Care to deal with the gate?

Bjorkas drops the bars, sets his hands in two lower spaces of the gate, and lifts hard. Str check +8
Total check: 22
The gate raises since Bjorkas can naturally power lift that much.

The member 'Bjorkas' has done the following action : Outcome

'D20' : 14

Loraatis moves through the gate and prepares to sprint to the door.

Bjorkas moves through and lets the gate fall behind him. He prepares to run and jump through the strange door. He looks for his weapons on the ground.
Spot check +1

The member 'Bjorkas' has done the following action : Outcome

'D20' : 9

He spots his weapons laying directly under the dimensional door. The dwarves all stand in front of the door making a barrier between the two and their escape.

Initiative mod +3

The member 'Bjorkas' has done the following action : Outcome

'D20' : 4

Initiative roll: -1

The member 'Loraatis Pegason' has done the following action : Outcome

'D20' : 6

The dwarves prepare for full defence and stand in a wall formation. "Don't let them pass!"

Bjorkas almost forgets that he can't kill them all on his own. Instead, he runs straight at the line and jumps right before entering axe range.

Jump mod +12

(I can't find anything for size modifier in jumping. There's a chart for reaching without jumping, but it seems that fine and colossal creatures can jump the same height with the same check. The best I can find is that characters can jump waist height with a DC 10 (about 3'8" for Bjorkas), and that every +4 on the check results in a foot higher for a med character.)

If I take 10, the check will be a 22. That comes out to a 6'8" Jump.
With the 17 roll, the check is a 29. That comes out to a 7'8" Jump.
Is that a reasonable system?

The member 'Bjorkas' has done the following action : Outcome

'D20' : 17