Hi Biscuit.
Don't be discouraged I too am new to electric power so here are some pics of my Bluebird.
I didn't set out to have a super scale model, I wanted one that would be fast and get up on it's wedges. I can agree with you on the quality of the moldings from TOUCHWOOD I only bought the main hull and the sponsons but I had to return mine as there were holes in the 45deg joint, but to be fare to TOUCHWOOD it was replaced with apologies and a complimentary tail fin and a set of decals.
My hull also had a convex bottom but as it wasn't to be a super scale I lived with it and it would possibly give a bit of lift.
Some of the mods that I made included grinding of all the rivets as they were about a scale as the rivets in the Queen Mary, a new tail fin was made from thin laminated ply and the sponson wedges increased in width at the rear of the sponsons, filled with balsa and skinned with thin plasti-card.
I have used 3/8" Ali tube as supports and have left them uncovered until i discovered how the boat performed.
The engine hatch is loose fitted and is taped up with water proof tape when running.
The drive system is a brushless 2750 kv motor with a 70 amp water cooled E.S.C. both purchased from Prestwich Model Center, the shaft is 3/16" dia St/St
and is at as shallow an angle as possible and the rear wedge has been left out as it could restrict the water flow to the prop which is a carbon fibre 37mm dia, battery is 8.4v x 3700 m amp.
I have tried to keep the boat as light as possible and have left out all baulk heads and resin molded fittings and now have a 1.5kg boat + 450g battery.
All I can say is that it is very fast and looks great on the water and I will be completing it soon, will send you some pics of it on the water when I can get my mates to photograph it at speed, I ccouldn't get pics as my radio is on it's last legs and so far have only had some short runs..
I can't say how yours will go with all the resin fittings and the Ali sponsons with the reduced area at the rear but have a go and don't get disheartened .
I have been involved with steam projects for some time so this is a bit of a diversion, have a look on STEAM R&D and see what I have been up to in the past.
George.