Lack of impact is more of an issue - and it is even more pronounced for the Healer profession because it is a hybrid profession and, as such, does not get the benefit of extra base spell lists as opposed to pure spellcasters.
I think you mean "because it is a hybrid profession, the Healer gets twice as many extra base lists as a pure spellcaster". Because in RMU, there are no "extra base lists" as such, but the cost of Open and Base lists is the same, so the pure caster gets effectively 10 "extra base lists", while the hybrid gets 20. The Healer has access to plenty of self-buffs through Mentalism and some decent lists in Channeling as well. They are kind of screwed on spell selection compared with the Sorcerer, in that a bunch of the Channeling lists are healing-based and hence pretty redundant. But still better off than the Mystic, whose base lists are all mash ups of Open and Closed lists from their two realms. (The Mystic, not the Healer, is the profession whose viability I am concerned with. And we got no or almost no playtest feedback on that profession.)
I would even say that I would expect at least part of that effort to go to spells that are useful in non-combat (or non-combat recovery) situations, but are useful for other activities (travel, social interactions, subterfuge, whatever).
They have access to most of these already, and the GM should be able to take into account social factors like a magical doctor generally being seen more positively than the scruffy mercenary that is the typical "adventurer". A little free healing will win friends pretty much anywhere, no other spells needed. And there is Sound's Way to overcome language barriers. Calm Spirits might also be counted into the "social interaction" bucket, in part. But for the rest...
Combat? -- Barrier Law (control the battlefield), Light's Way, Spell Defense, Calm Spirits (mostly to prevent combat, but some tactical options), Anticipations, Attack Avoidance, Brilliance, Damage Resistance, Seemings****, Spell Resistance, Telekinesis, Gas Manipulation, Liquid Manipulation, Speed
Travel? -- Light's Way, Lofty Movements, Purifications, Weather Ways, Creations, Locating Ways, Mounted Ways, Brilliance, Mind's Door, Movement
Subterfuge? -- Lofty Movements, Sound's Way, Cloaking, Seemings, Telekinesis, Sense Mastery, Shifting
Whatever? -- Detection Mastery, Light's Way*, Nature's Law, Weather Ways**, Locating Ways, Lore, Symbolic Ways***, Brilliance*, Delving, Detections, Gas Manipulation, Liquid Manipulation, Mind Mastery, Solid Manipulation
* Even if people don't need healing at the moment, being able to produce light without the risks of fire should always offer a chance to make a little coin.
** Another list that you can hire out or do giveaways for popularity (although you need to be better than those around you, as demand isn't as endless as for light)
*** You should probably be able to figure out how to make coin out of this list, too.
**** Probably a little creative thinking will let Seemings help out in a fair number of social interactions
This all seems more like an ideological objection to healing-centric professions than the result of actually playing one and finding it too limited (in RMU, as opposed to previous versions... in RM2, you were doing well to have all your Base lists by 3rd level). RMU casters have a lot of flexibility and can and should develop beyond their base lists (*especially* hybrids). The Healer can already buff himself quite well, if he so chooses, and being able to buff others would go against the feel of the profession. It could be more appropriate for the Lay Healer, perhaps as an alternative base list to replace Prosthetics.