Background: I'm starting a new campaign that everyone expects to last for a long time. This is a group that has already played a multi-year campaign to level 20. I played a wizard in that old campaign and loved it. (I know wizards can problematically outshine other players at high levels, but I was support-focused enough and they were focused enough on their damage dealing that it actually worked out well.) I was the last player to commit to joining the new campaign, so we already had a melee fighter tank, a ranger (or possibly rogue), and a bloodrager. A couple people might be willing to switch, but overall everyone is pretty committed to their characters and roles. Everyone, including the DM, recommends that I play a healer of some sort. I've spent really a very long time playing around with possible builds, including shamans, clerics, and even witches. But I miss my wizard. I have begun to question my group's basic presumption that every party needs a healer. Maybe it's not entirely motivated reasoning to think that what we really need is some form of an arcane CC/support/utility caster.
So what do you think? Could I go full wizard/arcanist, strand my party without a healer, and still have a decent party composition without my DM having to rescue us with a healer DMPC? (It is relevant to note that he is generally willing to provide us with pretty liberal access to diverse magic items.) If not, would a cleric/oracle cohort for mostly out-of-combat utility healing be sufficient in a party with no other healing? (I will also note that neither my DM nor I are huge fans of playing cohorts.)
Evidence in favor: I know there is a popular school of thought that damage is best prevented, not healed. Healing certainly can't keep pace with damage, and so eventually healing is a losing game in any battle that goes on long enough. In CRPGs I like to play heavy control parties with that general philosophy, although I usually find healing too useful to forgo altogether. Blitz attacker parties work on the same basic principle -- after all, if they're dead, they can't hurt you -- and this party might do well with that model as it has three main damage dealers. I can't help but remember that in my last campaign with this group, our battle oracle didn't spend much in-combat time healing, as he was far more effective as a self-buffed damage machine. As a wizard, I could help control the battlefield to make healing unnecessary, as I did in the last campaign. Magic items (or a cleric cohort, DM permitting) could help us heal outside of combat.
Evidence against: All of the above said, in-combat healing can definitely be dead useful. Sometimes you just need to give the DPS one more turn or two before they drop, and you can't always prevent all the damage (inevitably, enemies make all their saves, roll crazy high to hit, and so on). Also, someone needs to be able to deal with ability damage, status effects, etc., whether in combat or out. And while a wizard (or rogue) will eventually be able to UMD at least some of this if the DM allows enough access to magic items (which I think he would, and I could take magic creation feats to help), it'll be a problem at low levels due both to low UMD and limited gold.
(I should say that as large as my old wizard has become in my imagination, I also recognize that there are good versatile builds of several other classes. Hell, if you use Wandering Hex with a Shaman to get the Arcane Enlightenment hex of the Lore Spirit, you can straight up get rotating wizard spells, and my DM's liberal magic item policy could give me even more access to wizard magic, all on top of the Shaman's admittedly somewhat circumscribed existing mix of the witch, cleric, and druid lists. That's a fair way toward a non-crippled Mystic Theurge, which, if it were better, would be my ideal class -- I always want all the spells! That's all just to say that I think I probably could really like a character of a different class, even if I'm not nearly as drawn to them right now. What I most want to play is a versatile prepared support/utility caster with a good spell list. That sounds most like a wizard to me, but I'm willing to give anything a good look.)