I managed to get a party, one of my FC mates joined me and this time, it was a smooth run.
I went in as Scholar and healed it, didn't have the peace of mind to stand at a dummy and practice the new BLM rotation.
Now I do.

I generally watch video guides for new dungeons, so I had a rough idea what's coming up.
I also normally look where the others stand or run in certain situations and try to keep up. This worked fine, too.
Did the trial right after, then the other 2 dungeons for the expert roulette.

This was really a roadblock, but I have it out of the way now.

I'd like to add that my FC mates were running a PVP team.
They're not bad or unhelpful normally, they're just trying to get some action started as a community.
Me having weird shifts (as is often the case in Japan) didn't really help.

Doing DF isn't particularly helpful, especially not on our server, for stuff that's not basically instant gratification. Half of the groups are Alexander, the others Fates. Once in a blue moon something else pops up, so there's just no reason for people to even check what's going on.

Anyways, I got it done and like to thank you for your offers to help me out. It's really appreciated.
As for the problem at hand, I really hope SE does something about it. I'm sure the more time passes, the worse this will become.