Hi there,
Of the data you listed that you want to transfer, relationships and items like photos are difficult to move as they belong to "that Sim." For example, collectibles will remain in the house if you save each item individually in My Library, and they become the property of the Sim who purchased the house. I haven't tested whether game are recognized as same Sim to the Sim who purchased the house and the Sim in the photo, so I don't know. I think the same applies to diplomas. Achievements remain as the Sim's own data, so graduating from university should be recorded in the profile.
Regarding relationships, if they are family, saving them as a single household in the Library will retain the recognition of them being family. I don't remember if the relationship values remained the same. Sorry.
You mentioned starting with a new save, but if you could describe the extent of the save corruption in more detail, someone might know a solution.
In any case, please specify the platform you are playing on.