-Will temperature checks need to be taken at top of every call?

Most likely but who is in charge of this. Interested to hear what other industries are doing regarding this? Does this fall on an existing staff member or is it a new position? Health official?

-Sanitation stations, cleaning of surfaces before and after rehearsals.

Some rehearsal spaces I've worked in are just not satisfactory enough, they are old and run down. No matter how much you clean it doesn't feel sanitary. 

-What PPE would we expect to wear for cast and crew?

I would hope with adequate health checks and sanitary behaviour we would be able to avoid PPE, especially of a room is big enough to social distance 

-Closed rehearsal rooms? Limited access to ASM'S and Proppers? Closed to design team?

Easily done I would think

-Filming of rehearsals to be shared with design teams

Will this mean the company should invest in filming equipment? I never have enough space on my phone to record an entire run.

-Zoom/online production meetings

This has become a regular thing for me as I work with a lot of designers who are based abroad. Generally it works fine, however wifi in rehearsal/meeting rooms will need to work well which it often doesn't

-Storage of coats and bags outside of rehearsal room

Ideal situation yes, also means a less cluttered room which I love. Very often there are no secure places outside the room to do this though.

-Stricter rules around food and drink, everyone provide their own water bottles, tea cups, cutlery etc?

At this stage most people have their own water bottle/keep cup but this should be enforced. I've worked on a good few gigs where water bottles are bought for cast at the beginning of rehearsals. This has always been because of waste/environment etc but a simple email from the CSM before rehearsals start telling people to bring their own should cover it. I wouldn't worry about personal cutlery/plates etc if things are washed properly.

My concern is social distancing in a rehearsal room. With a cast of more than one, can they physically get close to each other? Less than 2mtr? Is up to the SM to say to the director, "They're getting a bit close now"?*

Is there a size guide for rehearsal rooms? ie; can we say a (insert amount of) personnel (cast, sm, director, poss design team?) needs x amount of social distancing space?

*It's reminding me of the slow dance on school tours with a priest moving people away from each other, "Make sure you leave room for the Holy Ghost"

The Venues/Rehearsal Spaces/Studios will need to set a maximum capacity for all rooms and spaces. This will inform cast and crew sizes. From the inception of the production the cast/company size will need to be considered as will the desired venue and rehearsal space. 

This is taken directly from SLUA's document for reopening arts centres, under production and facilities heading:

"Capacities to adhere to social distancing rules (2m). Spread out foyer furniture, negate or reconsider assembly points. There will be a need, for the event organisers, to show how isolation of individuals and groups will be managed at the event location. A general calculation on stage (as an area of movement) is 1 person per 6.5m2, the area capacity may change according to work type so consider in your capacity calculations. Follow current guidance as these capacity densities will change as more knowledge of the virus is known."