[@Jbcool] Waz ah melta?

No, but seriously, Urgrugg has no idea what any of those weapons do, or how to use them. Being a weirdboy, and not a mech boy, he doesn't just Know how to use tech. While he recognizes that technology is a thing that exists, and that it isn't warp-magic, he knows practically nothing about it. His magic has always been enough for him, and this is the first time he's been in a null zone for an extended enough period that it's relevant. Same would be true of opening the door, though that would be more because being a space marine vessel from the heresy era, it'd probably display in high gothic and he can only barely read low gothic.

As for being able to pull off the spell... short-range warp jumps are actually SOP for weird boys. Da Jump and Ere We Go are both examples of ork spells that could clear the gap, that can take the psyker and groups of 20-30 boys with him. Once he's outside the null zone, warp energy will flood back into him, so he'd have the raw power. Being an ork, he ignores wounds better than most space marines. So, once outside the ship, there's no great reason why he couldn't cast the spell.

Also, being 40k... wouldn't it be Caesar ex orkoid?