I have no problems using abilities or sythesis support, abilities are not he be all to end all of crafting. If you go into a synthesis that requires say Boneworking Training and you do not have the book, you automatically have a 25% chance of not completing the synthesis. I have seen abilities like Preserve which seems to keep your synthesis in a stable color for 6 turns help, same with the Makers Muse ability when used under the right conditions. I have seen some leves or synthesis require all 3 to be completed successfully. Usually I use Master Craftsmanship + Book + Abilities if a book is called for, or just master Craftsmanship + Abilities if no book is called for.