Is this class ability as crazy broken as I think it is, or am I misreading it?

Rashemi Spirit Magic (Ex): A hathran's training in the unique magic of her homeland gives her uncanny versatility. Beginning at 1st level, a hathran who prepares spells may choose to spontaneously cast any spell she knows in place of any spell of the same level that she has prepared, even if it is not on the same spell list as the substituted one. If the hathran normally does not prepare spells, she may instead utilize metamagic feats without the additional casting time normally required, though a spell so altered still uses up a higher-level spell slot, as normal. The hathran must be within the boundaries of Rashemen to use this ability, and there is no limit to the number of times she may do so.
So...this would give a Druid, or Cleric, access to spontaneously cast any Cleric or Druid spell?

Or a Druid 7/Cleric 1/Hathran 1 could spontaneously cast any Cleric or Druid spell, using their Druid spell slots???

I may be late to the discussion here, but that's bonkers! OK, it is limited to one (rather large) geographic location, but still. Could Acorn of Far Travel shenanigans be used to get around the geographic limitation?

I mean, I know many FR PrCs push the upper limits of power play, but I'd never stumbled across this particular ability until now.

Cheers - T