I started the game in HW and for me, the option to specialise came far too late in the game to be attractive.
I started out only intending to level 2 or 3 crafting classes, quickly realised it wouldn't work due to needing the cross-class skills and went down the omni-crafter route. By the time I'd levelled everything to 50, the option to concentrate on just 3 classes for the last 10 levels seemed pointless. Specialisation always felt like it was taking something away from me rather than offering something extra.

How would I change it?
-I'd offer specialisation much earlier, say around level 15. Put the quest in with the Guildmasters and let the Soulstone give the same boost to craftsmanship and control as you get now.
-I'd scrap the specialist abilities (I've never used them and I don't know anyone who does). Instead I'd do as Roth suggests above, let your specialist classes get access to all the cross-class skills as you level them. This would eliminate the need to level everything to 50.
-Annoying as the recipe locks can be at times, I'd keep them as it really does encourage you to make friends and cooperate.