ok some possibilies for you:
1. wait until everything is finished
2. split the collection. for example if it's a season of one show do the following:
- open the collection
- type "exx" into the filter, where xx is the last ep in that collection (so you have the right order after doing it)
- now only files from that ep should show up
- select them all and press split
- repeat for all other eps
3. download some blocks per default (see setup -> nzb -> Import as paused: par2 recovery files if size is greater then xx bytes.maybe you still have to start repairing manually while that collection is not finished yet
4. as said by you: unpause blocks manually
5. try importing the files as different collections whenever possible
I do option 2 most of the time if option 5 is not possible and i need the first set asap.