Can't help you with part 1 at all, but I had to ask long ago about similar questions to part 2, although my question was regarding the USD instead of GBP... basically the answer is that the CAD/GBP currency doesn't matter quite as much because presumably if the value of the pound goes down relative to the Canadian dollar, it will also go down relative to the other foreign currencies.
Let me try and explain this way, with numbers designed for easy conversion, not for any closeness to current exchange rates.
Let's say $1 GBP = $2 CDN today, and $1 GBP = $0.50 EUR. You have $20,000 CDN, so you convert it to $10,000 GBP's and they buy $5,000 Euro's worth of stocks. If the pound loses 20% of it's value against all other currencies because of their domestic situation, the exchange rates would be $1 GBP = $1.60 CDN and $1 GBP = $0.40 EUR... your ETF's holdings are still worth $5,000 Euros, but now that means it would be valued at $12,500 GBP, which would convert to $20,000 CDN.
Keep in mind that's super simplistic... any part of the ETF's holdings in GBP would drop in value, and if the CDN dollar goes up against the GBP because of CDN issues, there won't be that offsetting GBP/EUR change.
So basically, the answer is that effectively you are hedging the GBP, but no other currency, by doing that.
Let me try and explain this way, with numbers designed for easy conversion, not for any closeness to current exchange rates.
Let's say $1 GBP = $2 CDN today, and $1 GBP = $0.50 EUR. You have $20,000 CDN, so you convert it to $10,000 GBP's and they buy $5,000 Euro's worth of stocks. If the pound loses 20% of it's value against all other currencies because of their domestic situation, the exchange rates would be $1 GBP = $1.60 CDN and $1 GBP = $0.40 EUR... your ETF's holdings are still worth $5,000 Euros, but now that means it would be valued at $12,500 GBP, which would convert to $20,000 CDN.
Keep in mind that's super simplistic... any part of the ETF's holdings in GBP would drop in value, and if the CDN dollar goes up against the GBP because of CDN issues, there won't be that offsetting GBP/EUR change.
So basically, the answer is that effectively you are hedging the GBP, but no other currency, by doing that.
