Pdf sizes and page set-up

I just changed from 6.5. to 8.5 and find some major problems with score printing:
1.Pdf sizes seem to be enormous. A pdf from a project in 6.5 would be 1,6 MB. A pdf of the same score, now made in 8.5 is 57,4 MB. Something is definitely wrong. Anyone has a solution?
2.Page set-up is apparently not saved in the project. That is, if you work in A3 size, the page set-up will be in A4 when you re-open the project. And when you switch to A3 you will discover, that all the editing you have made in moving staves is lost. Problem! Anyone?