Crossword Puzzle Hard to differentiate

Clue: Hard to differentiate

Toiling hard (ATIT with 4 letters)
Kind of torch or hard (BLOW with 4 letters)
Kind of hard or torch (BLOW with 4 letters)
Hard-___ (tough) (e.g. EDGED with 5 letters)
Tossed hard (FLUNG with 5 letters)
Toss hard (HEAVE with 5 letters)
Hard to tote (HEAVY with 5 letters)
Hard as ___ (tough) (NAILS with 5 letters)
Hard-to-tolerate sort (PILL with 4 letters)
Modern dance music that supposedly mixes two genres that I'd be hard-pressed to differentiate, myself (DUBSTEP with 7 letters)