I think it’s clear that the Tories will be the largest party. The only real question is wether they have enough to govern with the DUP. If so, they’ll have no problem passing their agenda for the next couple of years.
I think they’d have major problems passing their agenda with the DUP. The DUP isn’t ever going to accept the Tory Brexit plan, built as it is on essentially leaving Northern Ireland alone in the customs union. And if Boris “Get Brexit Done” Johnson can’t even pass his Brexit plan, what hope does he have of achieving anything else? Honestly, that’s probably the worst scenario possible Brexit-wise. No majority for a Brexit deal and no majority for a second referendum.