I tried doing a search, so I apologise if this has been discussed previously.
We were struck by how many cool items are in the Mountain Wilderness and that you can buy at Ferro's, but if you follow the many walk-throughs available, it's forever before you see them, which is not only a delay but also means there's little of the game left to enjoy them.
So, we came up with the following. I'm wondering if anyone has tried something like this and/or if anyone has any thoughts on improving it.
Key assumption: Party has one person with Set Portal spell after reaching the T'Rang (via mine tunnels).
First, set portal in the T'rang teleporter room, and use it to teleport to the Umpani.
There, do the obstacle course and show the T'rang arm, buy up spellbooks you need from Kunar.
Next, run out to the Northern Wilderness, grab the diamond, clear the lake, and collect the Return to Portal book from the Hogar cave.
Then, cross the bridge into the Mountain Wilderness, run to Bela, stock up on Cloaks, Ankhs, Spears, Bows, or whatever your party can use.
Then, head straight for the waterfall. Collect bits. Follow south wall to Anselm's cave, then up to the bunker, collect more bits.
Then, use Return to Portal to get back to the T'rang. Complete flag quest, and kill Raven. Dont sell to Sadok, there's better value at Antone.
Next, use T'rang teleporter to teleport to Arnika. Collect Arresting Aria for Bard, sell bits from waterfall and bunker to Antone, meet with Mook. (and of course catch up on any mixing

)
Then, Return to Portal (or use the hut) back to the T'rang transporter room. Show Z'ant the Chaos Moliri, tell him the ship coordinates.
Finally, use the T'rang teleporter to go to the Rift. Fight through to Templar status, and trade with Ferro.
This then leaves you the Umpani Caves, underwater, marten's tomb, bayjin, and the Temple area to do with all your new toys (and full spell lists).
Some thoughts of my own:
If you can get everyone to level 11 (not too hard with a smaller party) before reaching Croc's there's no reason to run back through the swamp. Furthermore, it's possible to kill him straight off, and not worry about the kidnapping (although you miss out on the quest experience).
On the other hand, if you dont reach level 11 on the way out, run to Croc's before teleporting out from the T'rang to the Umpani, so that you maximise your spell books.
I've also experimented with skipping the return to Trynton to get the helm until after becoming a Templar as well, with no ill effect. This can seem to fit in anywhere before heading underwater.
thanks for your thoughts