Sell Otamendi and bring in Alderweireld. Instant upgrade and difference in transfer spend will be negligible (though will command higher wages).
If Danilo finds another club, get Alves on a free, though I would prefer that Danilo ends up staying.
Other than that, we're completely set. I wouldn't even bother signing another forward if Sane does end up leaving, as I think we're already going to have a couple of unhappy players come the end of the season. If we don't get to the latter rounds of the cups again, Pep's going to have a huge selection headache.
Shift Bernardo out to the wing (he can still cover CM if necessary) and place more trust in Foden.