So, Some Questions From A Returning Player...?

Add Dzemael Darkhold and Shposhae (I think this is what you meant by Cass Hollow?) to your dungeons list.

Castrum Novum is a stronghold, like U'Ghamaro Mines, Natalan, and Zahar'ak. Those aren't instanced.

I'd say strongholds are equivalent to places like Castle Oztroja - kill certain mobs for a coffer key to open a chest in that zone. The "big boss" in the stronghold drops a gold key that can open the three chests behind him.

There are also AF quests in strongholds - like getting your AF hands by clicking the ??? in the stronghold.

Also, the beastmen there drop the ex items used to enter the related primal fights.

Also the Boss NM's in strongholds drop the "broken" item piece needed for relic weapon quest.

North-west of 'The Nail' in Coerthas. Or east of the Gargoyle Crossing Bridge. There are two camps of R35-39 Hippocerfs consisting of about 8 mobs at each camp. They are easier to kill than raptors are and the two camps are reasonably close to one another. I would suggest setting your homepoints at camp dragonhead because, while they deal less damage than raptors, they can stun you and if you link a significant number of them by mistake they can stunlock you and kill you right quick. After gaining a few levels here, move back to the raptors and finally finish up at a stronghold.

For killing raptors, fight them from the side. They do breath from the front and have a nasty tail whip if you attack them from behind. Only have your DD's move front/rear if they are starting a combo and even then only for a moment.

Another option for that range is Copperbell Mines just off of camp horizon. It is a quick run north of Nophica and the mites are 35-39 in the lower level. Easy chains.

For Natalan, people will usually want 2~3 WAR (45+ for Steel Cyclone), ~2 WHM (40+, Regen/Stoneskin/Cure is all they desperately need).

Wolves are weak to WHM nukes, my Stonera would do ~650 or so when I was 45 without wearing any special gear. A BRD in the mix is a reasonable idea, more TP for the melee, more MP for the mages.

WAR's should be fine tanks for Natalan and Regen is usually enough to keep damage taken controlled. It's basically a FFXI merit PT, you'll likely pull 6-8 or so mobs at a time and have your WAR's bounce hate around with Steel Cyclone spam as much as they can (obviously any other DD will be bouncing a bit of hate too).

Some people are more selective with their PT setups. I've had people turn me down for PT's because I was 1 level under what they wanted.

When I got into my PT's for Natalan on WHM, I'd focus on healing and toss in nukes when I could (I'd Sacred Prism > Stoneskin then Regen any DD, curing as I needed). The other WHM(s) in my PT would nuke and backup heal.

On BLM, I'd run into the middle of a group and start Flare as soon as they were pulled, this was typically long enough for any WAR's to get Steel Cyclone off and then I could start a Fire combo.

I haven't played a DD to a high enough level to comment on them, but I assume they'd just play like normal with AoE skills (from what I've seen, all DD have ~1k hp more than me, so enmity isn't that big a deal).

A lot of it comes down to personal preference I guess, but I've always found this sort of setup works great.