"the rules are fairly clear and have few exceptions."
Many would dispute that!
A further complication in spoken Gaelic is the dialectal variation in pronunciation. For example, (maybe we're getting a bit off topic here), the verb "understand" is "duig" pronounced "tooeek" except on Lewis where it's pronounced "dig"; this has given rise in (American) English to expressions such as "I twig that" or "I dig that".