I'm not sure what you're talking about when you say, "On korriban, in the tomb, your character doesn't know bastila is bad." And who's the old bat? Keira? or Sion?
Getting cast out of the order does make this a bit awkward. But to explain that, we could just create (admittedly out of thin air) the assumption that the order noticed the force returning to the exile, and out of fear/mercy they decided to bring her back into the fold with hopes that a memory wipe will undo the side effects of a bad past. A jedi could easily travel to the outer reaches of space and accidentally find the exile and notice the return of the force.
As for "Does that mean if everyone liked her they wont think its a mockery?"
Not necessarily. "If X then Y" doesn't mean that "If ~X then ~Y." I'm just saying that some people never liked Bastila, so obviously they wouldn't like their exile being her. The idea is distasteful if the character is distasteful. Just like they wouldn't want the Exile to be Roseanne Barr. But as always there are exceptions to the rule.