A:  When using Interbase, the screen tries to update for every update.  If you disable the connections while performing actions like lookups or GotoKey, it will be much faster.  e.g.

dbLookupList1.Enabled := false;
dbGrid1.DataSource := nil;
dbLookupList1.Enabled := false;
with table1 do
begin
  setkey;
  fields[0].AsString := edit1.text;
  DisableControls;
  GotoKey;
  EnableControls;
end;
dbLookupList1.Enabled := true;
dbgrid1.DataSource := DataSource1;
LockWindowUpdate(0);