Cwrs Mynediad (De) South Previous 2005 Version - questions

I have been using both @Sarigne and @Serin courses and am so pleased you have worked to produce these. I could not find another forum for the South Wales versions. I was hoping to ask @Serin if the spelling for coat as côt was more commonly used because in Uned 12 we have ‘ei got e’ and ‘ei chot hi’ in the Part Two lessons 11-20 course. Thank you.

Some more queries about Uned 13 - time

After “mae hi’n” should there be a soft mutation i.e.

as well as:
mae hi’n ddau o’r gloch
mae hi’n ddeuddeg o’r gloch

but need also:
mae hi’n bedwar o’r gloch
mae hi’n bum munud wedi pedwar
mae hi’n ddeg munud wedi pedwar
mae hi’n bum munud ar hugain wedi pedwar
mae hi’n ddeg munud i bump
mae hi’n bum munud i bump