Re S2 "Sasse", I'm watching 'live' so don't have episodes to review but it so happens I have two still to watch at the w/e. If I hear another instance it's used, I'll post. Didn't realise that the discussion was about the books rather than the tv series. In any event, I'm new to the show and quite liking it but not obsessed by it. I made an observation (I think the tv show does use "Sasse" as a contraction for Sassenach) but demands to "be more precise" are probably going to fall on stony ground. ;-)
Ive read 5 of the books so far and watched the series never have I heard him say anything else besides Sassenach or Claire. It may be your hearing and his accent. My mother is hard of hearing and she misunderstands even with the hearing aids. Jamie uses the word Sassenach as a term of endearment. So he may also say it lovingly or soft like whisperly. He may call her something else in Gaelic. But i don't remember maybe once or twice. Referring to his fared hair girl or woman, something like that.