Consider TripIt. You can forward pretty much every receipt/confirmation/booking email to email@example.com, and it will automatically scrape them and add the details to your itinerary, which you can view on the web or in mobile apps for iOS and Android.
It doesn't have a built-in catalog of activities like inspirock does, but you can manually add events to your TripIt itinerary whenever you what. I'll sometimes fill in a TripIt itinerary with all my pre-booked reservations, then manually sprinkle in some possible activities like "maybe go to
Palatine Hill Tuesday" to give myself some notes. You can still use inspirock, along with guidebooks and other resources, for suggested activities, but keep your master itinerary and everything booked in advance organized in TripIt. Their Pro service adds a flight tracker, among other features, but the itinerary management is all in the free version.
Another option is Google Trips, for iOS and Android (not web), which scrapes your inbox for travel bookings and presents them along with activity suggestions.