My cures and status cures are generally of the form:
/ma "whatever spell" <stpc>
/equip
/equip
etc.
If I have my main target on a mob, then the sub-target cursor will default to me, then I can hit F2-F6 to target the appropriate party member if needed, and hit enter. (Can also tab around to any player nearby, in party or not.) If I have my main target on a player (usually only do this if they're outside the party or if I'm gonna repeatedly cast spells on the same person), then the sub-target cursor will default to whoever I have targeted, and I just hit enter.
It works better for correctly targeting spells than targeting them first, then using /ma "whatever spell" <t> - because if they equip swap between when I target them and when I hit the macro, the spell tends to end up aimed at me instead.
Granted, typing out the spell and their name by hand will always make sure it lands on the right person (provided you spell it all correctly), but it doesn't allow for equip swaps (well, you could hit a macro *to* equip swap during casting, but that's a little clunky), and it's usually slower. I typically only do it for healing people outside my party and then, only if it's easier to do that than to tab around and target them.
As far as keeping skills capped, WHM's a job that can actually get away with a certain amount of laziness in this regard. Divine is lol, enhancing you have to go out of your way to skillup anyway (and it doesn't help much besides barspells and stoneskin), healing has a fairly negligible effect. That just leaves enfeebling, which is a. easy to skillup (use Dia 1 on every mob; repeatedly if you've got nothing else to do and MP to spare) and b. often not needed (if you party with a RDM, let them enfeeble).
And Besieged works wonders for capping skills. Including healing and enhancing - buffing and curing Besieged NPCs gives skillups like debuffing/nuking high level mobs, which is nice. XD
As for the -na's to macro, the important ones are Erase, Paralyna, Silena, and Stona. The rest (Poisona, Blindna, Cursna, Viruna) are generally not particularly crucial to remove asap, and you can type them out or choose them from the menu.
(Oh, and in regards to Viruna - it costs 48 MP so don't overuse it. Non-resting frontliners don't need *disease* removed, but they do need *plague* removed. Disease just means you don't recover HP/MP while resting. Plague does that, *and* drains MP and TP. Thus disease can be ignored for anyone who doesn't rest.)