In the UK house run 230v. the socket ring will start/end in the fuse box usually in a 32Amp breaker. (go check your fuse box; often the rings are labeled). So you can draw 32*230 = 7360W on the entire ring. The highest rated fuse you will find in an appliance plug (including your A3; and yes the Bitmain APW3++ is the easiest way to go). 13 *230 = 2990W, therefore the maximum total wattage you can have plugged into an individual socket is 2990W. I believe you need to not exceed 80% of maximum load (someone please correct if wrong) of this if you are running continuously (like a miner). 80% of 2990W is 2392W. So in theory each socket can draw a max of 2392W until you reach the total ring load of 5888 (80% of 7360W).

Typically a washer will be around 700W but may go higher for shorter periods of time. All appliances will have a sticker telling you the info.

The A3 is 1186W and a washer of 700W so these could both be on the same ring (probably best not to have them in the same socket), with quite a few other appliances.

Again, I am not an electrician so if anyone else here has and more informed information please chip in. If in doubt get it checked!!!! But one miner shouldn't cause you an issue. What country are you in?

Places to host? There are various companies in various countries, so check the forum. I have recently started hosting with KPM Hosting (kpmhosting.com) in Canada, they post on here so use the search function and stick KPM in it or email them from their website.