Since you took your time to condivided your efforts and exerience, i will try to comment your awesome post at the best of my abilities.
DISCLAIMER: i used my build in a "abnormal" solo run, since i recruited some companions to do some stronghold quest. All that i will write comes from my memory, there can be some mistakes around.
As a remainder, if someone else want to try this build to try the ULTIMATE achivement, remember that:
1) potion are bugged : sometime the game start the "drinking animation" but nothing is going to happen. So if you want to risk and drink a healing potion when in low endurance, you can find yourself dead before you are really able to drink it. Try to drink it when you reach half health.
2) Blood testament gloves are bugged too : you need to re-equip them after every combat or they won't work. If that sicks you, just go for Ryona gloves or Accuracy gloves or speed gloves.
3) You don't need to "upgrade" the enemies (es: go to Stalwart after lvl 9) to earn the achivement.
First, I sold everything during the intro quest (for both of us) since that guy pays about 5x the normal prices. Then in gilded vale I killed the backer NPC near the temple entrance (can kill without anyone in town caring) to get their plate armor. That helped a lot. I rushed a few money making quests and bought the animat summon. He was useful to distract, heal, and help get mobs to stay in a line for torments reach.
I got the gloves and searing ring, and left the rest of rodricks alone for a while. I pushed to act II as fast as possible, getting to Stalwart at level 5 or 6 (stopped to get the shade summon, which I used the whole game). That was a pain, but there's a lot of good equipment and xp to be had there. It took MANY trips in and our of Stalwart (I could handle single ogres, up to 2, before needing to rest). Luckily it lets you leave Stalwart during the ambush.
Collected what equipment I could get quickly (boots of speed were really helpful early-mid and again when I fought Llenn) and then proceed to knock out WM1 quests. I did have to take a couple breaks due to running out of money (lots and lots of flame shield potions) so I did things like rodricks for quick cash.
Ok for selling everything at start, exept if you are tring to slay the whole caravan (i always do that for fun). In that case is useful to buy a weapon with reach (pike or quarterstaff) and a good armor, so you can corner yourself, let a single "paesant" hit you while you slowly kill the carvan boss, the guards, heodan and Calisca.
Plate armor, animat figurine, gloves of manipulation and seraing ring are the item you really need do get ASAP.
I always go to roedrick via upstair temple, speak with him, everyone is a friend now, loot the whole castle ---> more or less 3000 free gold
After finishing act 1 i take a different route. I'll wait to go to Stalwart until lvl 9-11, since as you noted the Ogres are by themself a bad machup for this build :slow hard hitters, with tons of hp, so your retaliation do little against them and you lose every battle a lot of health. They won't kill you, but kill them takes too much time and effort on low levels.
Usually is much safer to do some quest in town to lvl up and earn cash (march steel dagger, the svef smuggler quest, kill the thiefs in copperlane district to get a Droemel invitation, salty mast quests, brave Derrin quest, the Frontonero quest, the lighthouse quest(a bit later), ecc ecc
For sure i ALWAYS go ASAP for
- all the Droemel quest for the talent and the cash (3500 for selling the gem)
- Grab the shadow figurine from the Valian embassy (need 9 mech)
- the first crucibe knight quest for buy the "shood of faith boots"
- the quest for the Sanguine Plate --> YES, you can do it even in solo. You just have to speak with Pellagina after thet Droemels kills the merchant (i forgot his name). You don't need to have her in your party.
- The cemetery quests for : the Adra Beetle figurine AND the Gift of the machine talent
- Go to Drydford village ASAP just for buy the girdle of mortal protection (cheap and very useful at the beggining, no fight needed, you can buy it in the Leathersmith store)
Note that after that (that actually is early mid-game) you have 2/3 of the build already done.
Only after that i would go for Stalwart, no need to rush for it.
Ah nearly forgot: once you get in WM1 and beat the sige, do ASAP the ogre cave. If you do it WITHOUT KILL ANY OGRE INSIDE (the ogres outside doesn't count) [wich means sneak to the ice cave in the right, go down, kill the languefath, disarm a trap, kill the ice blights, go upstairs] you can have a farily peaceful discussion with the matron, and at the end you can go outside and find an ogre merchant where you can buy tempered helm and more important : fenwalkers. That item alone turns fight vs languefath in a cakewalk, no more paralyze for you at all or quite.
In most fights figurine are not even needed, but i always take 2 or 3 of them in the quick slot just in case
After you assembled the core of the build you can do more or less as you want. Usually i even start act 3 before go for Stalwart , for add to my equipment Aila Braccia (another antil languafeth/ range mbs tool) and Blood Testament (again no difficut combat involved)
My Thoughts for "hard" fights in the next post