Summoner has been my main job for years and I absolutely love it. However, there are some major limitations to it that I think are largely unnecessary.
The job is essentially a hybrid of spike damage and support. Because Summoner can do so many things, there are various ways in which the potency of any particular style is limited. This is understandable, of course, but I think it is done to an extent that makes us nearly worthless in either capacity in a group setting when compared to other jobs.
Damage
Summoner can put out some pretty impressive damage. However, only every 45 seconds (or up to 60 seconds if your equipment isn't fantastic). Between using the blood pacts, the damage of our avatars is insignificant. What I would want is an individual cool down for every blood pact, or at least a significantly reduced cool down for them.
The alternative would be some way to increase the damage of avatars while they are not using blood pacts. For example, an increased rate of double or triple attack, increased critical hit rate or just increased melee damage overall. Right now, Summoner's damage output is not substantial enough to be useful in a group setting when compared to Black Mage and other jobs. This isn't because our blood pacts aren't good enough, but because we can't use them often enough. To me, lowering the cool down would be fair because of the high MP cost of blood pacts and because we are already limited in that we have to release and re-summon avatars if we want to use a different element of damage or a different buff.
Support
There are various forms of support we have spread across all of the avatars. The problem here is that we are basically limited to using one or two at a time. If we want to give our party members Garuda's Hastega and also Fenrir's Ecliptic Howl, we have to summon, buff, release, summon, buff, release. This takes quite a bit of time and because of how much time it takes, we aren't able to do any sort of damage in between, so the versatility disappears, especially since other jobs can do the same things much faster. My solution for this would be to either significantly lower the casting time for avatars (to the point where the casting time is about the same as the elementals), or to make the buffs so substantial that they are worth the effort. The sad fact is that there are few things a Summoner can provide that other jobs can't. Perhaps Summoner buffs can be extended to an entire alliance instead of just one party, or perhaps Summoner's can have some sort of cure or buff that no other job has.
I wanted to mention Avatar's Favor here as well. Avatar's Favor had a lot of potential, but is also unnecessarily limited as far as I'm concerned. For example, the range on it is very limiting. If I want to use Diabolos's Favor to give refresh to the mages, I have to just let Diabolos sit there and do nothing. Plus, I can't switch avatars because then the effect will reset. I would suggest that Favor be a constant effect that doesn't require the use of the job ability to take effect. As a compromise, take away the decreased perpetuation and the decreased damage output that comes with Favor being active. I would also suggest that the "Aura" sort of effect come from the Summoner him or herself instead of the avatar, so that I could hypothetically put the buff wherever I want it to be.
The Summoner
The main problem for Summoner in every aspect is the unfortunate problem of only being able to have one Summon out at once, each with its own set of abilities. This obviously is necessary, and in many ways a very positive thing. However, to really make Summoner unique and more useful, there needs to be some way to get around this so that we can be more versatile. My idea is to give the Summoner itself, distinct from the Avatar, a bit of power too.
My fantasy, if you will, is that there would be a set of spells specifically for Summoner to be used in addition to the summons. Perhaps there could be spells that are less potent versions of Summon buffs. These would not stack with their corresponding avatar buffs but be overridden by them. Keep it from being overpowered by making it so that if you release an avatar, the effects wear off. Also make it so that you must have an avatar out in order to use them. There could also be restrictions based on the element of the avatar you have out. For example, say you make a spell that is a reduced version of Garuda's Hastega. If I have Shiva out, I can't use it because of the conflicting elements of wind and ice. This would force Summoner to be more tactical and strategic, while still enhancing their abilities and making them more versatile.
Specific examples:
-A spell that would give a single target Shiva's Frost Armor (Ice Spikes), as long as Ifrit isn't summoned.
-A spell that would be a single target version of Leviathan's Spring Water, provided that Ramuh is not summoned.
Each of these could be limited in various ways to prevent them from becoming overpowered. Perhaps the use of a spell would reset the blood pact timer, or perhaps every active buff from the Summoner can add to perpetuation cost. The overall purpose of this is to allow Summoners to provide the various buffs they have access to, but without having to constantly shuffle through avatars, which is very time consuming. However, there remains incentive to do so because of the increased benefits of the Avatar's versions of these effects.
This could apply for offensive abilities too. Perhaps, for example, if Shiva is out, the Summoner gains access to some ice-based debuffs or damage over time spells.
Non Summoner Related Stuff
Early level progression
Some of my best memories with Final Fantasy XI are the ones where I'm grinding in places like Yhoater Jungle and Quicksand Caves, places people never visit anymore for experience. I have embraced the Grounds of Valor method of leveling lower level jobs whole-heartedly. I think it makes the leveling experience much more fluid and fun because it's not so redundant and slow.
However, I feel there needs to be some incentive for people to explore some of these overlooked areas. One way could be to replace Fields of Valor entirely with Grounds of Valor. Put those books in every zone so that there is incentive to exp EVERYWHERE, not just in areas with Grounds of Valor.
Also, give players some reason to go to higher level areas to earn exp so that they can in turn learn how to play their jobs more effectively. The exp in Gusgen Mines is so great at every level that there is no reason to go anywhere else. The only thing newer players learn how to do now is kill the same skeleton over and over and over. Perhaps augment Level Sync slightly. Level Sync was ingenious when it first was released, but is now outdated in a game that doesn't revolve around moving from place to place to grind. I would suggest putting some sort of limit on how far down you can sync or greatly lowering experience at higher levels so that players can't stay in Gusgen mines forever.
However, the elephant in the room here is Abyssea. I am a huge fan of Abyssea and what it has done for the leveling process. However, I very much miss leveling up the old fashion way. Why can't there be a way to get experience as good as what you'd get in Abyssea, but in older areas that are closer to the players level so they can learn how to play the game and experience all of the beautiful locations FFXI has to offer? I also think that the minimum level for Abyssea should probably be raised so something like 50 or 60, since getting level 30 these days takes so little time.
I hope none of this is redundant. If you took the time to read all of this, thank you so much. I know that was a ton to read, and it means a lot that you take the time to read what your players and customers have to say. For the record, I have played since about 2005 and I am a huge fan of the game. I have played countless modern MMOs that don't hold a candle to FFXI as far as the community and atmosphere. Thank you for keeping this awesome game going for such a long time and continuing to improve it ten years later. =)