Sorry I DO find there is often an assumption that because someone is from a different culture they'll be insensitive, dim idiots from some social backwater with no family or communication skills
This isn't how I feel at all, but DH feels as you do, he says many people in UK make these assumptions about anyone from a different culture. I usually tell him he is being over-sensitive but maybe he is picking up on undercurrents I'm not aware with.
FWIW I wouldn't let my own parents take DS out without me either.
The cultural difference I referred to was more re views on guests, family roles etc. DH says in his culture it's normal for family to stay for few months to help with baby, female relatives take over running of household, personal space is unimportant, everything is shared and guest is offered the best of everything (best room, best food etc). In Western culture there is more emphasis on privacy, space, not being intrusive. When my parents visit they get a hotel because they feel our flat is too cramped! DH finds this offensive and thinks they are cold.
I've only met my PILs on 1 occasion, several years ago (when we married) as they were unable to obtain a visa until last year. So yes, maybe when I know them better I'll feel more confident.
I do appreciate they are excited about meeting grandson and I don't want to spoil that with rules... I'll get DH to tactfully drip-feed a couple of boundaries and the others I'll just establish at the time eg asking what time they want to take a shower and encouraging a routine to develop.
I don't feel I need to be in the same room as DS, I'm happy for them to take him while I rest/shower/nap just not take him out of flat. DH has never taken him out alone, he has suggested it but I'm not ready. I've left them alone at home for few hours and he baths DS without me present (after promising to watch him the whole time and not turn his back or play with phone while he's in the water). I've heard too many stories about babies drowning in shallow bath-water to be able to relax about this.
Re breakfast I'll do as suggested, just grab something early then have a cup of tea with everyone later.
I like the suggestion of having a calendar on wall with weekly timetable of events and times, DH could write in the translation so PILs know what's happening each day and can plan things on days when we're busy. I have a class 4days a week so need to be up early some days.
Thanks everyone, I'm feeling less anxious about the visit now! I do want it to be a happy 5weeks. I'd like to become close as a family and feel comfortable around each other. But I also know I take time to warm up new to people, I'm quite introverted and used to my own space. It feels like a big jump!