You won't pop your boat using a SCUBA reg LP outlet, provided you keep a hand on the tube and check it (as you would if hand pumping it). I'd think your biggest risk (assuming no overpressure valves) is leaving her in the sun when pumped up.
I don't have a pic of my kit and I think it would only muddy the water, it's based around a very old AP Valves inflator and you won't have one. The pressure differences are minimal so just find a bit of hose that fits your RIB valve and insert/fix the SCUBA inflator to the other end - away you go.
Tip: Duct tape is your friend