Odd measures

Hi! When I try to create the kind of notes you can see in the pic, it takes forever to manually change every measure to the correct number of beats. I cant change one and copy the rest, and it is impossible to marque several and change at once.

I want the alla breve in the beginning, but the measures may have a lot of beats, or maybe different amount of beats.

The example in the pic is an old hymn made by Martin Luther in the 16th century.

I also have examples of even older music for mass (to play when the priest or leader sing), where I would like notes to have the value "until next note, or when measure ends". Alla breve note (looks like the one last in the song in the pic) has a fixed number (8/4). Can it be made to last "as long as needed"?

This music is old kind of music with no fixed number of beats, and sometimes very odd. Until now I have worked A LOT to make it look ok. The one in my example pic is rather easy, 5 halfs per measue. But I just can change one measure at the time. :/