I don’t have any advice on your first question I’m afraid but I’m sure others will!
To answer this, I expect that this is the type of service that Monzo will enable you to purchase through their marketplace.
It sounds like this will work a bit like a price comparison site & you’ll be given a choice of providers to choose from. I like the idea of being able to choose the appropriate cover for me, rather than having to go with the one option that my legacy bank provides…I’d be interested to hear your thoughts on this too 
In case you’re interested, there’s been some more discussion about how travel insurance could be made ‘smart’ here too -