2) only the animas vibe and tandem tslim (which isn't available in the uk) links to G4
3) so far only animas has announced a pump that will integrate with G5. I think that recieved regulatory approval in the US in December 2016. There is no date for trials or availability of the planned animas one touch vibe. The likelihood of any date being announced in the near future must be rather slim given the commercial position of animas at the moment - Johnson & Johnson (parent company) are considering "strategic options" for it diabetes care companies.
Tandem might be workin on something to integrate with G5, but I don't think any things been confirmed/announced. And tandem aren't available in the uk anyway.
Tandem's T;Slim X2 is supposed to receive a firmware update later this year to allow it to read G5 data, however, no dates have been given, Tandem's share price is in the bin and it's not available in the UK.