This is mostly for the OP, but I quote you because I feel your initial sentence is not correct.
Holding hate is actually pretty easy, even at the lower levels (it's pretty much the same thing though). The trick is using your skills in combination with your available targets while dispensing some flashes when needed. Spread out your threat increasing attacks to your secondary or third/fourth mobs instead of just focusing on your primary target. This seems to be a hard thing for a lot of inexperienced tanks to understand and get right. I've seen level 50 i80-i90 Paladins who never learned these simple mechanics, and what happens is if you're in a group that does aoe damage (or one dps that doesn't seem to want to attack the same target as everybody else) then your dps pulls aggro from you and makes things generally more difficult than they need to be. A good healer and at least 1 good dps can offset a poor tank's lack of aggro management if they can notice and respond accordingly to what's happening. This is something I've had to do many times when I've hopped on my Whm to do Low level and High level Duty Roulettes, even back when I was leveling my Pug/Mnk and Lnc/Drg concurrently I experienced this.
Maybe I was lucky but I learned how to tank well by watching the good tanks I leveled up with on my first class/job, Acn/Smn, and remembered what they did. Now, I haven't leveled my Gld or Mrd up very far but on either when I had run dungeons on them the players I had in my parties seemed to be amazed at how well I held aggro.
Yeah, it's extremely different than how just about any other MMORPG works it's tanks (which tends to be: TAUNTFLASHPROVOKE, dps, [or toss in some self cures depending on the game] rinse & repeat). But after coming to understand it and how the combo skills work, it's actually not too bad. Just takes a little getting used to at first.