Valuable how? What are the benefits? We already know the disadvantage is not being able to queue your heals and thus using actions slower than you would without macros, and also the possibility of lag messing up your macro by skipping steps, which I guess can cause using the action on wrong target (or not using it at all?), but I'm not 100% confident about this so please correct me if I'm wrong.
We all know you can heal with macros (while you can't really play a DPS with macros), but I don't think there's a reason why anyone should. For me, having played healer both ways, it felt much more unresponsive and clunky healing with them, and being able to queue your abilities is an obvious, objective benefit.
There are many healers playing at top level healing with macros, so don't worry, you should be able to play with them just fine, if there are no other issues (such as lag messing up your macros).
Are you using mouseover from party menu or having your mouse over the actual player character you're trying to heal?