Re 6: you can avoid the mayoral letters by pretending to have a hotel booking. You can easily make and then cancel said booking using, eg, venere.com. I have done this frequently on grounds of it being easier than getting my actual hosts to get proper letters.

Re 7: what?! Need visas to visit UK now? Quelle horreur...

Re crash space: we has it. Comfortable, even (nice futon! own bathroom!). But there will be a crying baby in the house, so, hm, possible detraction from comfort levels. One hour from St P. Close to Heathrow.

Re socialising: yes ma'am! ...it would probably be helpful if such arrangements could be baby-friendly.

scroob