It seems I didn't go into enough detail in the topics you mentioned because mostly your concerns don't match with my intentions.
1. This is the one thing where I just fundamentally disagree. Not everything needs to be equally good at something as everything else, nor should it be. For example casters are simply better at nuking mob packs than melees. There will always be a meta composition for any fight. Pick two different fights and you get two different optimal compositions. There was a japanese team that cleared an ultimate world first and everyone was surprised when the team had a DRK, which at the time was considered the worst tank class. When asked why, the player just said "cause it's fun". I'd prefer things to be slightly more imbalanced if it gives jobs a more unique identity.
That aside, my issue with Dancers is that they were supposed to be "the" support class but in the end they're just a dps that just happens to support a bit more. My suggestion is to split dancer into full support, hybrid (what we have now) and full dps. With full support they basically stop being a dps and just provide very strong buffs for the full party.
2. I'm not suggesting there should be a fixed timer on the hunts. People should still have to go around finding them and probably only S ranks should get that special treatment. Aside from that I don't see your problem with my suggestion. Server load and instances is something the devs should worry about.
3. I'm not a summoner main and don't play it enough to say more about it than "it feels too simple". I just don't think summoner isn't much of a summoner without his summons. Removing the pet aspect of the class feels like a lazy fix to me.
4. Job customization shouldn't result in a difference in DPS output. In it's most basic form, my suggestion is make the skill green instead of blue because I like green more. These customization options should only give a difference in feel, no more.
5. My intention here is for weapons to basically be new jobs with the theme of the base job. Not horizontal progression.
6. I don't see how my suggestions require complete redesigns. Can you elaborate here? They're surface level suggestions on purpose precisely because I don't know what's possible to do. They're suggestions that the devs can draw inspiration from, not completed systems that you only need to plug into the game and you're done.