Look at the legislation. If they're a problem you need to be able to get rid of them.
The "what if.."s need to have answers before you start - it's YOUR home/property.
If they're technically speaking "Lodgers" then you have one set of rules, if it's a renter then it's another. But HMG isn't saying anything about those rules, yet. You can't evict for non payment of rent if they aren't paying any, so ---- what?? They'll need money for absolutely everything. I would expect them to sublet, run sidelines to earn a bit of money, etc. What are you going to do, deport them?
I've heard people saying how these poor ordinary people like us just want a roof and they'd be grateful etc. Partly true, for a while..
Don't forget they mostly don't speak English. The kids pick some English up off the street. Their second language is Russian. The ones who speak on TV are selected, obviously. I was in Ukraine about 12 and 25 ish years ago. Outside hotels, it was mostly sign language, and some very broken German and English, pretty scruffy poor people. It improved, but checking now, a data centre worker earns about £250- £200 a month.
Outside the city centres, things looked poorer than our shabby social housing, with teenagers in gangs, "unemployables" widespread, like most poorish countries. No where near as smart as say Poland.
I don't think it's pejorative to suggest that integration/accommodation may not be as trouble-free as we might hope.
For those without family ties, I would expect most would be happier to stay in closer countries than the UK - closer in many ways.
It may also be a cheaper option to pay the neighbouring countries, the amounts we're looking at giving our local authorities and individuals - the money would go further.
