where are you going with this?
a 3 level dip in Oracle + the rest in bard isn't going to be something unplayable or something,
although your energy body will not scale (in rounds/day) and neither will Channel,
and obviously your bardic advancement will be delayed 3 levels.
have you looked at the cleric 'Evangelist' archetype from Ultimate Combat? it gives you some Bardic Performances in exchange for a Domain (leaving you 1 Domain) and Medium Armor Proficiency (leaving you Light), and changing your Spontaneous Casting from Cure/Inflict Spells to a list of Social/Enchantment spells.
Why do you want to dip bard at all?
In terms of optimization thats really no good idea.
Sure, someone with your stats could play a bard; but in my opinion, it's inefficient to multiclass out of oracle. Depending on the party makeup, I could see maybe taking a level or two in a full BAB class. However, even a prestige class that advances your oracle spells per day would still leave behind your oracle's curse, bonus spells, channel energy, and so on. Even rage prophet -- which was designed specifically for oracles -- is billed as emphasizing the "fighting prowess" side of things. Just something to consider.
To answer your other question, your curse of tongues will affect your use of language-dependent spells and abilities in battle. Other spells and abilities will be unaffected, but (for example) you can only give a command to someone who understands your stress language, if you're under stress.
I don't plan to dip this early; I want to do it around my 8th-10th level.
Um... your 1st post says when you get Level 2 healing spells you want to multiclass into Bard... That should be 4th level (I mis-spoke when I said 3rd). Again: what in the hell are trying to do here? Are you planning on going full Bard after switching over, or just dipping in Bard a bit, and going back into Oracle?
I like your suggestion but will my curse of tongues affect my use of spells in battle?
My suggestion of Evangelist Cleric?
I meant that as a single-class build that accomplished Divine Casting and Bardic Peformance with no multi-classing. You COULD combine it with Oracle, but your Oracle abilities won't scale with non-Oracle levels (besides Rage Prophet).Anyhow, to your question about Spellcasting/Curse of Tongues...
I don't think Spellcasting is affected, beyond issuing commands to targets (which is really outside the spellcasting itself). Vocal components of spells aren't really 'words' or 'language' per se, they are just vocal spellcasting components. This would be a problem for ANY Oracle with that curse if that were true, and I haven't seen anybody have that problem in a game.