Well as you've chosen a mining guild as your faction base extremely strong military vessels aren't exactly the most logical choice of ship class. A mix of transports and medium escorts makes more sense to me. Perhaps refine your ranking system based off of a real life petroleum corporation?
I ask now will you be RPing the actual transport of H-Fuel and its related commodities? If so then you can certainly justify armed escorts for you convoys in high pirate areas. I must say that it is somewhat unfair of you to become irritated with the community for nit picking your faction, considering thats what this post is basically for. We've seen far too many YANFs already, be forgiving if we're skeptical.
I would personally love to see a proper and working GMG faction myself, so I'm on your side. One suggestions is uniform naming conventions for your members. In game I've already seen two separate [Gcorp] taged players with different capitalisations of their names.
Ex.
[Gcorp]-XXXX
[GCorp]XXXX
Over all it does not give a complete and professional feel to your faction, and that saddens me as an RP enthusiast. I must say thought that GMG using Kusari ships makes no more sense to me than a LPI tagged player flying a Falcata, yes I've seen it. I would consider sticking to IMG and Rheinland vessels, it makes more RP sense really( as well as civilian ships).