Excellent and well written post. I have a few additions to make post level 65, if you do not mind from what I have seen, in your gear selection:
Necks: Skill Torques (Elemental, Enfeebling, etc) These give +7 skill each to their appropriate skill, which is the equivilent of casting as if you were 2-3 levels higher than you really are. This may not seem like much, but I did experimenting with these, and items like Holy Phial, etc for MND....these are by far the best necks you can get for an experience party, and you can macro swap them back and forth so you use which you need when. You can also macro it back with either the Rank 8 Bastok Neck, Fenrir Torque, or just simply a Spirit Torque/Holy Phial for MP on a Convert. Also, these necks are not very expensive for how powerful they really are, only 100,000 to 200,000 gil a piece and well worth every gil.
Capes: At level 71, the Rainbow and Prism capes become available, think of these as Red Capes on steroids. They not only give you bonus to both MND and INT, they also provide more MP and a very nice MP and HP boost as well. If you can afford the Prism go for it, but the Rainbow is still very good for its cost. I've also been contemplating an Enhancing Mantle for Convert purposes, no stats but +10 MP and + % to it as well is decent, and for a 70 RDM/BLM it results in about +17 MP total. The cost is at MND and INT so it would not be every day wear.
Earrings: I would like to add in the potential for the Enhancing Earring. It is only level 40 usable, but results in +5 both HP AND MP, and is very reasonably costed. I personally like this paired with a Morion and a Phantom Earring. The new Latent effect level 30 earrings are interesting as well, as more information becomes available on these, as some have very potent Latent effects (+30 MP, +5 Enfeebling Skill, etc). But beyond that, Earrings for all jobs are fairly weak and hard to find good ones for.
Rings: Once you pass the 65 level, you can probably start whacking Avatar Primes with parties, I STRONGLY Suggest you do them a few times and pick up their rings. Leviathan's gives +15 to Conserve MP skill, Shiva's +15 Elemental Skill, Garuda's +15 Evasion, Titan's +15 Defense, and Ramuh's +15 Accuracy, but only on their respective days. It may not seem like that much, but these are well worth it.
Swords: Lots of good swords start showing up post level 65, but many are hard as **** to obtain.
Joyeause (Spelling) - Need to kill an NM for it, but is nice for farming resulting in occasional double attacks, also good for skilling up, every extra swing = an extra chance to skill up.
Enhancing Sword - Rare as all ****, but pretty much the pinnacle of red mage swords, Accuracy, Attack, and good ratio all rolled into one with a + to enspell damage.
Analace and Analace +1 - Very good Ratio weapons, and both Red Mage usable, Analace +1 is pretty much the best Damage/Delay ratio weapon a Red Mage can use besides Excalibur, but is beyond rare to find, I have yet to ever see one for sale in the AH.
New sword I dont know the name of - There is a new sword that is now usable by Red Mages at level 73, it has good ratio and stats, and has +18 MP, looks very promising.
Excalibur - If you thought Enhancing sword was rare, don't even think about this one, however it does give access to the final Sword weapon skill.
Staffs: Post level 51, Elemental Staffs become available, these are also very good, and result in some potent abilities. For Red Mages, I believe, Light, Dark and Ice are the most powerful, resulting in + Cure Spell potency, + MP/Tic healed up, and + Elemental Skill. I strongly suggest these to all red mages and to macro them in and out as needed.
Belts: RSE Belts, the level 50 and 70 ones. These are both expensive as all ****...resulting in a ton of gil spent, however these result in a lot of MP and + MND, INT or both...these do come at a cost though, many have - Melee stats in trade, but for some 45 MP is worth a few points of Strength, when you also get + 4 MND and 3 INT...