> That said, I thought that the rule in the UK was generally that the loser pays the winners costs
That’s generally true… but only happens after those costs have been incurred and probably paid.
There’s no guarantee the party suing will be able to cover their own costs and the defendant’s costs. That leaves OP on the hook for defence costs with the hope that they might get them back after a successful and likely expensive defence.
In that situation, I can understand why OP wouldn’t want to take the risk.
That depends on your living situation. I live in a third-floor apartment, so weight is very definitely a factor.