adding to-dos to the calendar: some ideas

i would like to put to-dos on the calendar in a way that shows me how much i can realistically get done on that day.

my ideal workflow would be like this:

i enter to-dos in my inbox. then i pull a to-do on my calendar and it STAYS a to-do, it does NOT become an event. why? because if i manage to complete this to-do before the scheduled time, i don't want to have to remove the event by hand (as a reminder that this time is available again)

right now, i can do something similar by pulling the to-do on the schedule tab. but there is a problem with this: in the calendar these to-dos show only as a single grey line at their due time, even if i have entered a start time for it. but if it is a to-do that will take me 3 hours to complete, i want to SEE on my calendar that these 3 hours are blocked and i can't do anything else at that time.

for me this would be the feature that makes a fantastic app perfect! :-)