#2
I asked Mathias Jaschhof, one of the experts in strange midges in the Sciaroidea about this interesting specimen (because I did not fancy this as Limoniidae). His reply:
Interesting indeed! Judged from wing venation, I would not exclude the possibility that it belongs to the base of Sciaroidea, possibly somewhere near Diadocidiidae, Ditomyiidae or Keroplatidae. The gestalt is even slightly cecidomyiid-like. One should see the specimen. Apparently a cave-dweller? That would explain the reduced morphology, such as narrow wings.
#4
The wing reminded me of
Trentepohlia, but it's not an exact match. Check whether there are two anal veins and the typical crane fly suture across the thorax. Also check for ocelli -- absent in crane flies, usually present in fungus gnats.