To build a new wooden boat, you can use epoxy for ease of use and performance. Or then use the traditional methods which don't require using epoxy at all. If one has thick enough and good enough lumber I can't see a reason to use epoxy on a small boat. Everything can be done without glue, and if the boat is done without glue it's always easier to repair or replace a damaged piece when you don't have to fight with glued seams.That was the idea with classics: when something was broken you could pull the broken piece out and replace it. It just doesn't do with epoxied structures.
Of course using epoxy is not out of the question. It just shouldn't be the default or "essential boatbuilding material". There is no actual need to use epoxy on the maintenance of a basically sound wooden boat which has been built without it. Restoring or bigger repairs are always a different case.
In restoring a classic wooden boat, you should use traditional materials in a traditional manner. This is even more important if you are doing major reparations or a complete rebuild. New material and new building techniques will leave nothing of the original, new material with original techniques will fit in much better. The only exeptions to this should be allowed if the desired strenght of the structure cannot be achieved without epoxygluing.
Using epoxy is sometimes handy and may save you from taking too much of the original apart. There are places that can be quite easily repaired with epoxy. Doing things "the traditional way" can require taking down much more of the original structures. If something is rotten, it is absolutely wrong to try to substitute the rotten wood with epoxy or a plastic putty. The only right way is to repair it with new wood.
Oils and epoxy shouldn't be used together. If something is to be glued with epoxy, oil impregnation should be done afterwards, not before gluing. Epoxy might not bond properly on a previously oil-treated surface, so in case you have to use epoxy, clean the surface with acetone or such.
When doing a repair on a classic boat you should avoid using epoxy as a sealer. Excluding the fact that on a real classic you will ruin some of its historical value, you are more likely creating just pockets where the water gets in but can't get out. Epoxy encapsulation works, but it should be used only if the encapsulation is done while building the boat. It is almost impossible to encapsulate a ready structure reliably and that will result to a situation where there is water trapped inside the wood and it can't evaporate. And that means that the wet wood freezes at the wintertime and it is destroyed in a few years.
In restoration work epoxy is a great glue, but it shouldn't be used to bond together things that should be able to move. The original designer has designed the boat accepting the fact that the structure will move some, and depending on it. Now when you stiffen part of the structure with epoxy, something else will break.
Wood movement, UV light, scratchs and knocks may break the epoxy surface. So, it's not as "service-free" as one would think. You have to keep the surface in perfect condition to keep the water out.
Covering the whole boat with epoxy and/or fiberglass should be reserved to the most hopeless cases of rotting fish traps. The trick which may extend the life of a wreck for a few years may as well turn a reasonably sound boat into an un-repairable and quite worthless junk that has very little value. After fiberglassing the hull there is not much left to do. The process can't be reversed.
Otherwise there is no general rules in salvaging those absolutely hopeless cases. You can use ethylene glycol, fiberglass, anything you can think of, but only if you are absolutely sure that there is no other options.
I saw a great little motorboat last year, and found an article about it in a Finnish wooden boat magazine. The boat was very thoroughly restored: in fact only thing there was left of the old construction was the keel, five planks and a few parts of the small cabin. It just shows that some poor fool can find a boat where everyone else sees a just hopeless wreck.
I wouldn't have put so much effort on such a wreck. But the owner is more than happy with it. Don't consider your wooden boat a wreck before asking someone who knows.