Oh well, when I still played ffxi, it was in 2006. I don't play that much anymore what I used to, besides, I don't want ffxiv to be ffxi all over again. Camping stuff for hours and hours.. and then someone else taking your claim. I think every mmo should be rewarding, so that no matter what you do, you will get the things you want sooner or later, there really shouldn't be things that _only_ depend on luck. If you're unlucky, you might end up using a lot of time to get those items while someone gets them with 1 try, but those who keep trying it over and over again, will eventually get their items. This would eliminate the feeling that you're wasting your time with trying to get an item you desire and I think that'd be a good thing, but I do say that I don't want things to be too easy, not at all.
Let's just say, for example, if you open the coffer chest like 50 times, you will get your item forcedly on that 50th try. After that the counter resets to 0, or if you manage to obtain the item before you get to 50 tries the counter resets to 0, so it can't be misused for personal gain. A number of tries so ridiculous, that one should definitely get it before that, but some people are just unlucky and this would be a life saver for them. Note that this is just an example of what I mean with this.
If the mob would drop a key every time, then the chests drop % would be a lower than it is now in return. I wouldn't really mind opening the chest even a hundred times, it would just feel less like a waste of time when you'd always even get a little chance to obtain the item. It'd be better than not having a chance to obtain it at all. Oh and if the mob would drop a key every time, then it should be like a hundred tries or something to get it 100% from the chest.. make it reasonable in comparison what change would be made for it. Then you could just say well, I didn't get it today, but maybe I will tomorrow and not feel bad for not even getting a key to try it and feel like you just wasted 2 hours of your time for nothing, still knowing that you will eventually get it on the 100th try.