Hey, I think you got much further than me in some respects and not as much in others. I like that the game allows for that to happen. I have been personally satisfied with my experience playing it a short while ago and have dropped it for now to clear time for making my own game, lol. Anyhow, of what you mentioned, here's what I have figured out for now:
(decode these with rot13: https://rot13.com/)
On the TOWN family: Vs lbh'er gnyxvat nobhg gur tebhc V'z guvaxvat bs (Gur guerr "V" sbyxf va gur pnir jvgu gur erfcnjavat zbafgref) V xabj jurer gurl raq hc, vg'f gur gval ohvyqvat ng gur obggbz bs gur qrfreg nern, qverpgyl haqrearngu gur pnaavonyf. Ohg V qb abg xabj jul gurl qvqa'g tb gurer ba lbhe raq evtug nsgre pyrnevat gur zbafgref va gur ebbz gurl'er va. Gung'f jung gurl qvq ba zl raq. Znlor gur tnzr qbrfa'g guvax lbh sbhaq gur furygre. Gel rkcyvpvgyl vagrenpgvat jvgu vg be fbzrguvat? Znlor.
On the blue sigil doors: Gur qrirybcre uvagrq gbjneqf guvf gb zr zber rkcyvpvgyl va gur tyvgpu eryngrq guernq. Ohg va oevrs, lbh pna xvyy gur perngher gung fubjf hc fbzrgvzrf jura lbh cvpx hc gur fjbeq. Naq fbzrguvat pbby znl unccra vs lbh qb vg n tbbq srj gvzrf. guvf bcraf hc n tbbq srj nirahrf va GBJA va n fbeg bs pnfpnqvat jnl.
On getting cursed again: Gel uvqvat va orq sbe n juvyr :)
On the PONCHO: Lbh trg vg vairfgvat na nofheq nzbhag bs NTR vagb TVEY. Yvxr n erny tebff abg rira shaal nzbhag. V qba'g erzrzore rknpgyl ubj zhpu. V gevrq gung ba n fnir jurer V unq n erny ovt fgnfu naq fur tnir vg gb zr.
Haven't figured out anything you haven't regarding the missing stew ingredients or the huge root veg. I was wondering - do you know how to make the cloy combustible yourself? I THINK I have the ingredients but don't know how to dry the towerlung in my inventory with the matches like instructed in the book on the matter.. I don't remember seeing a creature in rail trail, either. I'd agree that combining items does feel like pretty much a dead end if you don't receive explicit reference towards a certain combination. I don't know how much I'd like it if it was any other way though.
Best of wishes / luck !