typical all-in loss with pocket As for non-experienced player,
normally loss in pre-flop all in is normal because you have the best hand pre-flop, after flop any card can flod with a good read of the other player's hand ( you can flod set, straight which are much stronger than pair of As only)

i am not very good but just want to share my experience, read card plus betting pattern plus tells,
tells can't know here, so
1st case is ok
3rd case is wrong play, being reveiwed already,
2nd case may have chance to reduce the loss,
SB bets $1.75, may steal the pot but can call $6 raise means has something in hand
after flop SB check, may hit or not, if not hit anything, only a small bet can bet him out, only a few player or very experienced aggressive player can use weak hand to call reraise and to bluff after flop,
after flop SB hits, you bet $11 will surely make him reraise all in you,and you can't run for pot-committed,
so we study his hand first, pocket Ks is not big chance because he will reraise or all-in you preflop, then it may be a poket pair bigger than 9 and up to Q to call the reraise pre-flop, Qs or Js is the biggest chance, if not pocket pairs, the chance to call is AK, then AQ, if not then suited connectors
so after flop JQ7 rainbow, the biggest chance to reraise you all-in is set (this reraise will not expect you to flod because you are pot-committed already, so it is a real hand) or open-end straight draw (but it is not worth for heads up play), or AQ or JQ suited (this 2 cases has less chance),
so my comment is : after flop can bet less and flod with a reraise all-in fight back

difference between 1st and 2nd hand:
in 1st hand, he has lots of chance to get other losing hands to push you all-in, such as pocket Qs or even 10s (because only 1 over card outside, so only loss to Js is the most reasonable read and this only case can't make you flod your As)

moreover, 1st hand Ks may not reraise you (you reraise a real hand raise means a strong hand), 2nd hand Ks will reraise you normally (to test your reraise is a catching of bluff steal or a real hand reraise)