Here are some insults and epithets that are ungendered and not ableist.
From dharma_slut-- (I've taken out a few that I dislike for one reason or another, click the link for full list):
blundering, brutish, feckless, foolish,
heedless, impulsive, inadvertent, inconsiderate,
indelicate, insensitive, instinctive, mechanical,
negligent, oblivious, outrageous,
rash, rude, selfish, senseless, tactless,
thoughtless, uncaring, unconscious, undiplomatic,
unheeding, unintended, unmeant, unmindful,
unpremeditated, unreasoning, untactful,
unwise, vacant, witless, abrupt, abusive,
bad-mannered, barbarian*, barbaric*, barbarous*, blunt,
boorish, brusque, brutish, cheeky,
churlish, coarse, crabbed, crude, curt,
discourteous, graceless, gross, gruff, ignorant,
impertinent, impolite, impudent,
inconsiderate, insolent, insulting, intrusive,
loutish, low, obscene, offhand, peremptory,
raw, scurrilous, short, surly, uncivil,
uncivilized, uncouth, uncultured*, uneducated,
ungracious, unmannerly, unpolished, unrefined,
vulgar...
----
Others:
Ridiculous, silly,
sour, spoiled, putrid, rancid,
raw, uncooked, smells like wet dog,
unproofed, full of weeds, untilled, had no beta reader, unsexy,
goofy, grimy, out of proportion, out of tune, out of balance,
not on the level, unfair, all hat and no cattle,
And just plain BAD.
ETA more: cracked leather, trims no trees, tarnished
*Please see comments at LJ concerning possible racist connotations of these terms.
From dharma_slut-- (I've taken out a few that I dislike for one reason or another, click the link for full list):
blundering, brutish, feckless, foolish,
heedless, impulsive, inadvertent, inconsiderate,
indelicate, insensitive, instinctive, mechanical,
negligent, oblivious, outrageous,
rash, rude, selfish, senseless, tactless,
thoughtless, uncaring, unconscious, undiplomatic,
unheeding, unintended, unmeant, unmindful,
unpremeditated, unreasoning, untactful,
unwise, vacant, witless, abrupt, abusive,
bad-mannered, barbarian*, barbaric*, barbarous*, blunt,
boorish, brusque, brutish, cheeky,
churlish, coarse, crabbed, crude, curt,
discourteous, graceless, gross, gruff, ignorant,
impertinent, impolite, impudent,
inconsiderate, insolent, insulting, intrusive,
loutish, low, obscene, offhand, peremptory,
raw, scurrilous, short, surly, uncivil,
uncivilized, uncouth, uncultured*, uneducated,
ungracious, unmannerly, unpolished, unrefined,
vulgar...
----
Others:
Ridiculous, silly,
sour, spoiled, putrid, rancid,
raw, uncooked, smells like wet dog,
unproofed, full of weeds, untilled, had no beta reader, unsexy,
goofy, grimy, out of proportion, out of tune, out of balance,
not on the level, unfair, all hat and no cattle,
And just plain BAD.
ETA more: cracked leather, trims no trees, tarnished
*Please see comments at LJ concerning possible racist connotations of these terms.