What do you do after the Jelly in Crawl Sprint I: "Red Sonja"?

⚠ Spoilers ahead

My usual route around the first part of the level is: (× mark doors that get me killed)

Stairs → Ijyb → Ogre → Sigmund → Gold → Giant amoeba × Kobold demonologists → MORE FUN GOES HERE
                  ↕               ↓
                Gold       Gold Items
                              ↕   ↓
        Store ← Elephant slug ← Jelly × Centaur warriors → Bee
                                  ×         ↓               ↓
                                S         Items           Oklob ? Tr
                                 o          ↕             plant   ap
                     Shop     ←   n   →  Rock troll → Shops       do 
                        ×          j                              or
              Giant eyeballs        a         Invisible baddies ← sp
              Shining eyes        ×                   ↓           id
              Jackals         Gas spores      Pulsating lumps   ← er
                   ↓          Gold+Itemsn     Ghouls + gt eyebl   ×4
                 Shops                            ↓        ↓
                                                 Shop galore!

As you can see, I'm pretty much stuck at the Jelly room.

• Sonja is pretty much certain death: the son of kobold can choose between more than enough curare-tipped needles, a whip of electrocution of a dagger of distortion, complimented by her blinking spell. Berserker is completely useless here.
• The kobold demonologists are even worse, with or without some source of warding. Demon spamming for the lose.
• The two centaur warriors also can make a very short job of me. Their ranged attack is deadly and while the fog does help getting in closer range.

What should I do next? Is TrBe too much of a one trick dog, perhaps? Should I go for more traditional combos like DDNe or SpEn?

Well, I can generally get past the centaurs just fine. The demonologists and Sonja are certainly chancey though.

I always turn off all skills except unarmed combat till I get UC to around 20. Skills like dodging are total drains for troll berserkers.

You get maximum UC speed at skill 25, when you have a speed of 5. This is twice as fast as Sonja with either needles or dagger. Throw on a berserk boost, and watch 'em fall.

I found this column at GameSetWatch, it has a nice explanation of Dungeon Sprint mode.