I didn't say that Feyspeaker cannot be a capable melee presence, what I said was that 1/2 BAB hurts it, and that that stat distribution is not optimal.
From my perspective I'm not certain that giving up 3/4 BAB and all the bonuses you get from, for example, DOTW, is worth the bonus spells that Feyspeaker gets access to, not to mention that it's much more MAD due to reliance on CHA
Feyspeaker, in conjunction with a Thasillonian Specialist (Conjuration), is a great combination for a Mystic Theurge:
1. Take Feyspeaker (Fire Domain).
2. Take Thassilonian Specialist (Conjuration).
3. Install "Call of the Wild" (for those extra druid spells) and "Favored Class" (for traits).
4. Pick "Magical Knack" as a trait. That way you will gain caster levels in both classes until hitting Mystic Theurge.
5. With Thasillonian Specialist, you gain additional TWO spell slots per spell level. And what do you lose. Evocation and Illusion spells...
6. Feyspeaker has Illusion spells, and the Fire Domain will restore some of those Evocation spells. You also gain an additional spell slot per spell level.
7. You'll be swimming in spells very quickly, and won't lose any of their power thanks to Magical Knack.
8. Since you need both Intelligence and Charisma, items which increase both, like the Crown, will give you a double dip, adding spell slots to both classes.
9. "Call of the Wild" also restores Spell Synergy, the 10th level Mystic Theurge ability allowing you to cast two spells at once.
10. Take Aasimar (Peri-Blooded) as race, since they gain +2 to both Charisma and Intelligence. That extra offensive spell is also useful.
11. Take Viper as Familiar. If you boost your Charisma to 18, you'll start with 12 points in Diplomacy, and be a glass cannon and skill monkey simultaneously.
