There's no problem at all with necroing threads. If you want to liven up an old thread with new feedback, be my guest. I honestly don't understand why some forums have rules against thread necro, since many old threads are good ones and there's nothing wrong with the conversation picking up again where it left off, and I feel like those forums tend to have moderators who feel obligated to create rules and enforce them just so they can feel like they're moderators. Not to mention it's just a pain when you're websearching for information on some topic and you find a forum thread that's useful but just old enough to be missing a lot of newer material or insights and no one was willing to post the newer stuff to that thread because that would be "thread necro" so now you have less helpful threads to look through and get to hope that maybe there is another thread that does have the information you want.
Using the multimorph discovery is a pretty good option, but then you need to obtain the
Shapechanger bloodline as a
Wizard (or be a 10th level
Blood Arcanist using the
Arcane Discovery exploit), which means either you went MAD and took enough charisma (perhaps using a
pink and green sphere ioun stone), you are playing an old age or even venerable Wizard (and thus dumped charisma to 7 which became 9 or 10 with age modifier) and decided to wear a +6
Headband of Mental Prowess to qualify, or you are playing a
Human Wizard with the Draconic Heritage and Focused Study alternate race traits so you could take the Eldritch Heritage feats without the charisma prerequisite and then used an
Ampoule of False Blood to convert it into a Shapechanger bloodline. You can also obtain the Shapechanger bloodline with
Bloatmage 10 (but this would require having a creature with the shapechanger subtype on hand, which could be yourself if you're playing a
Kitsune with the Keen Kitsune alternate race trait or
Skinwalker with the Werebat or Wererat subrace) or by entering
Dragon Disciple (using an Arcane Bond to satisfy the prerequisite of being able to cast 1st level spells without preparation) and using an Ampoule of False Blood again to swap all the bloodline powers for Shapechanger ones (but you will want the
Favored Prestige Class and
Prestigious Spellcaster feats to cover dead levels). Honestly, Dragon Disciple with Prestigious Spellcaster is a pretty solid PrC for Wizards, since it gives free AC, a d12 hit die, and a free +2 to constitution and int at higher levels. If you play an
Exploiter Wizard you can also use the
Bloodline Development exploit to stack Wizard levels with your Dragon Disciple levels for bloodline powers, but you will either need an
Eldritch Heritage (Arcane) to qualify (which will also get overridden by Ampoule of False Blood, causing a bit of a rules mess unless you decide to simply keep the
Draconic bloodline, which is really only appealing if you are perhaps using
Bloodline Familiars,
Bloodline Mutations, and expanded draconic options to replace the energy resistance perk with limited DR, but that means you don't have the Shapechanger bloodline...) or have to wait until you dip a level of
Loremaster for
Secret of Magical Discipline to fulfill the prerequisite by letting you cast 1st level spells without preparation.
Performing the Paragon Surge stunt as a Wizard opens up some unusual options in the form of picking up
Preferred Spell (or extra
Spell Specialization feats while you have a
Greater Spell Specialization feat, but that limits you to schools you have
Spell Focus in) to spontaneously cast a spell of your choosing. Then there's the usual
Spell Perfection and
Additional Traits (
Wayang Spellhunter and
Magical Lineage). The Additional Traits trick can actually be used on prepared casters with partial spell preparation (
Quick Preparation feat and/or Fast Study
discovery may come in handy if you are doing this loads) to repeatedly prepare slots with 1 or 2 levels' worth of free metamagic then exchange your bonus feat for something else while the spells remain prepared at discounted levels. (For instance, you can give all your spells
Silent Spell for invisible casting or
Still Spell for armored casting - or even shapeshifted casting provided you use a method to obtain the ability to cast
Beastspeak, like the
Magaambyan Arcanist PrC.) Similarly, you can take
metamagic feats, prepare the metamagicked spells, then switch out the feat. It's also possible to just use leave it in the form of humbler feats like
Improved Initiative or
Skill Focus (Perception), of course.
Using
Create Sanguine Elixir (which flat-out requires Sorcerer levels) with
Alchemical Allocation is a pretty good stunt tbh, but getting Alchemical Allocation generally requires an Alchemist in the party, a dip into
Pathfinder Savant or
Daivrat (borrowing from the
Antiquarian Investigator which is an arcane spellcaster using the Alchemist list), or a
Ring of Spell Knowledge (probably providing the arcane version of Alchemical Allocation with a scroll or casting of
Limited Wish, and remember you can UMD the ring to avoid level penalties), unless you feel like repeatedly casting
Limited Wish for it. It's also possible to use the
Sage (replace your shitty new 1st level bloodline power with the Arcane
Bloodline Familiar) or
Empyreal wildblooded bloodlines with
Samsaran race for Mystic Past Life (Antiquarian Investigator in previous life), but then either your GM lets you combine with wildblooded with
crossblooded (I would, frankly.) or you need to get 15 cha for
Improved Eldritch Heritage (Shapechanger), but being an old (or venerable) Sage Sorcerer is both thematic and extra beneficial as it lets you start with 22 int (and therefore you can take 7 spells with Mystic Past Life, instead of the usual 6), although you'll need to fix your con score, maybe take a Toughness feat, and perhaps give your familiar the
Protector archetype. Then again if you're a Sage Sorcerer you can also just use your bloodline feat for a prereq and aim for
Loremaster so you can get the bonus feat immediately for
Secret of Magical Discipline, which you can also use to fuel a Ring of Spell Knowledge (but you'll want the
Pragmatic Activator magic trait or
Clever Wordplay social trait to make UMD int-based if you want to UMD the ring).
Oh, and I should probably mention an oldie of a method for permanent Paragon Surge: Just use
Paragon Surge inside a timeless demiplane you created with
Create Greater Demiplane. The problem with this, of course, is that it requires 9th level spells.