I am a Veteran player. I have most of all available jobs to 50 but Warrior and White mage. I have cleared most of the end game content, save for Coil T5 and Ifirt Ex, as various roles, from Tank, Caster Dps, Melee DPS as well as Healer. While i am not saying I fully understand everything about the game but I am confident to having a firm solid basic and some advanced knowledge.
Newbie, I prefer to someone who has no job yet to lv 50.
To melee DPS: I have both Monk and Dragoon to 50,so I have a basic knowledge how both class's skill required direction to have maximum effect. Now as a Tank, being a Maurauder lv 24 on top of it, you have to understand that my job is to holding aggro in the most effective way with the least resources spent. Unlike Paladin who has Flash which affect all mobs around him in 360 degree as long as they are close enough,I ,Marauder,as low level, only have Overpower as AOE threat generate tool, and it only affects in cone shape in front of me. That means, if a pack of mobs is scattered, I have to do a few spin around at the start to make sure Overpower connects them all to establish proper threat. I always ask the DPS to go nut with no holding back, however that does not mean you have to jump the big gun right at the start. When I do the tanking, unlike others to mark the target and such and being the one who control which to attack first, I am very flexible by allowing DPS to pick whatever target they want and tank accordingly. So far, i have no trouble by doing so and I received a lot of commendation for that.
Now, while I do understand that melee has the disadvantage of relying on direction to deal maximum damage, Monk relies more than Dragoon, at least not until you are lv 30 and above, as a Tank, I will do what it takes to protect the rest of the party from the mobs, even if it means that I have to reposition them here and then. i am doing my best to make the life of the rest of the party easier, meanwhile, you can also help me making my job easier by not throwing your insult around when you miss the addition effect or potency for not being in the correct position because I am in the middle of grasping all of their attention or wait for me until I finish my job.I assure you by using your Dots skill or using your normal combo which does not require postion or wait for 1-2 sec will not make your DPS drop from awesome to rubbish. It is not the matter of life and death when you miss your optimal effect on Trash Mobs, but it will be when these mobs start coming after you or healer. And when it happens, the first thing coming will be "Tank sucks,noob,...etc", and I will be the one to be flamed at, no one else. I have zero tolerance to those who ask me to work extra harder,so that they can slack off by sitting on one place and spam 1 skill mindless with the risk of not doing my job properly, especially not from any of those newbie who does not even get to the end-game content. I will and always will left if I meet those kinds and it is your loss, not mine. Sure I will get penalty by leaving but as being a Veteran player, I have much more things to do while waiting for my penalty goes off plus I have the luxury of instatnt queue. On the contrary, you DPS usually has to wait a long time to get a pop plus if you keep that attitude up, you will be the only one suffer later on.
I am saying this not as a Tank, I can be all high and mighty but as a Veteran player want to give you an advice : "It is ok if you are new,it is ok for not knowing but it is not ok for you, as new, acting as you understand fully well how the game works, your job, being arrogant and starting to insult when things not going your way".
To Healer : Most of people, they expect the Tank to be the leader of the team and have a smooth run without many wiping. And to be able to do that, the Tank has a good knowledge of the dungeon the team is running. Whenever, we are able to rush through the boss without too much concern about the side mechanic, the Tank will suggest to do so and would love to have everyone cooperation to make the run a nice and smooth run.
For instance: The Fire Sprite in Hatali, it is easy to burn down the boss without worrying much about the AOE when the fire minions get to the Flame. With one or two Medica as Conjurer, you can keep the whole party up without worry a thing about being chased by boss or the adds. Now with that being said, Healer should not go chase after the adds, DPS them down by themselves and let the whole party wiped because the Healer forget to heal the party. When the Tank suggest that, Medica is safe to use in that situation and more efficiency, the Healer should not do and spam nothing but Medica for the rest of the run, just to prove that Medical can pull threat of the Tank (though it still requires 5 Medica Spam to get the mobs come after you) nor let the Tank die for not healing and laugh for being undergeared Tank. What wrong with having ilv 20 Gear to run a lv 20 Dun like Hatali while the Healer is in the lv 15 Item himself?
Furthermore, you are a Healer, your job is to Heal the party, not to DPS, and so focus that the Tank died because you forget to heal then flaming on the Tank for not doing his job. If you think you love DPS that much ,why choose a Conjurer to start with? I just don't understand. Sure you can DPS but only when it is safe to do so and only when you think you can still doing a proper healing while doing extra DPS.
Being a Healer, your main priority is Healing, not DPS, not tanking. And if you are good at it, you are a Good healer and be able to DPS is a bonus and we sure love you for that. Otherwise, please only focus on healing.