Since you do not want to have a premade build handed to you, I'm going to focus on where I see specific skills that could be replaced and why, rather than just dumping replacement builds on you. Actually, most of your existing builds are fairly solid already, so you're better off just tuning them as you go along and could just as easily ignore everything I say and be perfectly fine. Ogden's build is the only real exception.
OQZDApwDCas7GocROZQD
I'm assuming Meteor is there for knockdown rather than damage. With Panic added to your build you probably have enough general suppression already. You might want to go Monk secondary and add a hard res, see below.
Ether Feast is good in Pre-Searing, bad once you have a party. Your Monk(s) should be doing the healing. I would recommend replacing it, again, with another interrupt or damage skill.
No other real feedback to make, it's a good Mesmer build.
OwAT043A5BAUSyI0VQSMxiUXBA
Light of Deliverance is ok, everything else here is pretty bad.
OwAS8YIHzEA1rirMmBUl
This is actually not too bad.
I main Monk so I'll go into detail here, unlike with the others. So when designing a hybrid monk build (the preferred Monk build) you generally want the following: one power heal, one minor heal, one spot protection for rapid incoming damage, one heavier protection skill for high pressure, condition removal, hex removal (if you have to pick between one or the other, take hex removal), some form of energy management, and Aegis, unless you have some other source of party-wide block.
I actually usually take all my healing in one elite skill, Glimmer of Life (since it covers spot healing and you can also spam it), but generally speaking (and in the case of heroes) a good pairing is Word of Healing and some minor healing skill like Patient Spirit or Dwayna's Kiss.
You have Mend Ailment on Tahlkora's bar, which is good although Dismiss Condition is the best if you've invested in Protection Prayers already. I would take either of those skills and put it into Ogden's bar to replace Purge Conditions. Purge Conditions is very situational and its long recharge makes it not too good. I'm assuming you were going for synergy between Martyr and Purge. Which actually makes sense if your entire party was getting hit by shittons of conditions, but I don't know how well the AI would micro those skills and suspect such conditions are rare outside of, say, Mandragors in EotN.
I'd get some hex removal in there; Cure Hex is best if you've invested in healing prayers but Remove Hex is also solid and is No Attribute. In some cases RH is better. It doesn't heal, but it recharges as fast as you're going to get for most hex removal.
Shielding Hands, Reversal of Fortune, and Aegis are all great.
Healing Breeze is terrible in general PvE and I'd get rid of it.
For Tahlkora, since you're going with protection/condition removal theme here, I'd replace Martyr with Restore Conditions. You can get that one in the Ring of Fire and it's actually a really good skill that'll be a lot more flexible than Martyr. I'd set her secondary to Mesmer, throw six points into Inspiration Magic, and add Power Drain and Leech Signet to her bar, and ditch Resurrect.
A monk should never carry a res skill; any other party member can fit one by going Monk secondary in but Monk bars are generally at a premium for space. Most professions I can make a build and be at some leisure on what goes into my last few open slots. With Monk I am always plagued with the dilemma on how to compress everything I need into just eight skill slots. Monk has no room for res.
As I mentioned above your slot currently taken by Meteor would be a good candidate. This is doubly good because as a human you can probably escape from a potential party wipe better than the AI could, and then get everyone ressed. You'll also probably handle in-combat resurrection better.
For Ogden, it's kind of hard to suggest improving the existing build because I would replace every skill on it, personally. I'd go back to the Crystal Desert and grab Word of Healing. Add another heal for backup like Patient Spirit or Dwayna's Kiss. Skip condition removal if you do plan to run RC on Tahlkora, but fit Remove Hex in there. A couple of energy management skills. Tahlkora has SH and PS already, so maybe Shield of Absorption and Guardian on the Ogden, if you are ok with a hybrid build. Possibly Signet of Rejuvenation. I never like to run pure Healing Builds besides sometimes a UA hero, and UA is as cookie cutter shit as it gets.
OQBDAqwDCnowB5cRG9gC
I'd drop Hex Breaker and Mantra of Flame, same goes for Ether Feast. For the same reasons described on your build - leave defense to your monks, and have your Mesmers focus on dishing out as much damage as possible. And again there build is otherwise pretty solid. I'd focus on getting more damage dealing interrupts in there. Between Power Drain and Leech Signet the build has enough energy to support them.
OgBDkoysOvichwYsaMQG4CaB
Probably fine for now. I'm not a fan of Mind Burn, but it's not bad either. Sometimes, especially lategame, it can be hard to have more energy than many AI enemies, which would be my only real concern with that one. Most of the elite skills I'd use on an Elementalist hero are later in Nightfall.
OgmkcWp8Kxuj0NAPgFvlX77+VDD
No comment other than that I personally try to avoid using melee heroes; the AI isn't good at the role. I can't really offer any feedback because I haven't really played Dervish since the update and I don't know what constitutes good build design for that profession, especially for a hero. I would replace with another profession when able. You don't actually need a melee character in your party and most people these days do just run pure caster parties unless they themselves are a melee profession.