2 targets?

Would it be possible for us to maintain 2 targets at all times? 1 ally and 1 enemy. Abilities only target one or the other, never allowing both, so why not? It's just an extra convenience that we are denied for no real reason. You don't need the full display for the ally, just leave them highlighted in the party menu and keep the enemy up so you can always watch its cast bar. Allowing dual targeting would be a large boon for things like healer dps, or not losing your mob target in a large group when moving to goad/etc. an ally.

That's what Focus Target is for.

If you can write macros correctly as a healer you can keep you tank targeted for heals and cast on the mob without switching targets. And those same macros can be used for direct targeting as well if you're solo if written correctly.

If you need to have direct targeting on the mob, focus target whichever ally you want and write the appropriate macro which can also be used for direct targeting. Its in the game, a little more complicated then you probably want it, but that makes it super customizable.

Focus target can also just be used so you don't loose your main target in the crowd and watch their casts, hp, debuffs and such as you take care of adds.

If you focus target the mob you can keep an eye on cast bar, debuffs, buffs and such then just switch to the tank. Viola.

Quick Example for dps spells on healer

/ac "Stone II" <t>
/ac "Stone II" <tt>

this one will cast stone 2 on whatever you have targeted, but if you have the tank targeted, it will cast on whatever they have targeted. You could also use <ft> to cast on your focus target instead of your target's target.
Like so.

/ac "Stone II" <t>
/ac "Stone II" <ft>

For something like goad, I would focus target the ally most likely to need goad in any given situation and write it like this

/ac Goad <t>
/ac Goad <ft>

It will then goad your focus target if your target is not an ally, which it likely won't be as a dps

Just do some google research, the things you can do with macros is nearly limitless and not nearly as complicated as it seems.

Doesn't work for me. Whenever someone gets themselves into trouble I need to quickly smoke them, shadewalker the tank, and dps whatever they pulled to get it back on the tank. Problem is, it's hard to click or tab back to the mob in a timely manner when it's in the middle of a large pull. I can't just do what you're saying since you never know who's going to need it and when. I see no reason why XIV can't use a dual target system like other MMOs do. Your target ally should not affect your normal combat targeting.

Focus Target macros are better than nothing, and since they're the best the game currently offers for this it's worth knowing how to set them up. But I agree with Callback that dual targets would work better, as it would allow both changing our ally target and enemy target on the run more easily than having to change focus target in advance. Healers can perhaps anticipate that the tank is going to need the majority of their healing, but lots of jobs use TP so it's a lot harder to predict who might need something like Goad.