Interesting subject this is. Especially today when we have several variants of resins such as polyester, epoxy resins, then Eze-Kote resin which is water soluble and the two previous ones are not.
First of all, I think we have to decide why we are actually coating the hull? It depends what the hull is actually made from; under normal circumstances the softer the material that the hull exterior is made from and the more water absorbent it is. The greater the need to put a barrier on the exterior of the hull - so basically the hull itself should be strong enough and not need any re-enforcement of fibre glass material. We should only use it as a barrier. Having said that, there are many balsa wood hulls and brown gum-stripped hulls which have had a paint & sand n sealer coating and sometimes a shellac coating to protect the exterior - and they are still around today from many years ago - a tribute to the build.
So, if the hull is made from a good strong birch ply in theory we should only be required to fill the gaps where mistakes were made in the joints of the hull skin with some form of filler and then fill the grain of the plywood with some recommended filler and then carry on finishing the hull with the paint or varnish. No need to try and add extra strength with tissue mat or woven roving and resins.
The main thing people seem to fall down on is whether to coat the inside of a hull as well the exterior and the answer I think should be yes - as wooden material when damp tends to swell and if a plastic material has been used to coat the exterior to form a barrier - it will not expand when it's damp. Therefore the wood may have a tendency to break away from this exterior barrier. If we coat the interior of the hull as well as the exterior we are preventing any dampness entering the timber, therefore preventing any swelling/movement of the wood.
Regarding confidence and working with resins - confidence is only gained by trying as everyone knows - so therefore as has been suggested it does pay you to practice on a scrap bit of wood. Especially today with the water soluble resins, if it is going wrong we can always quickly wash it off with warm water and soap - as I have done myself in the past.
That's my thoughts
John