Q: Questions about Photos . . .

After migrating an older iMac to a new one with Yosemite, I have some questions about Photos, the successor to iPhoto:

-- Can the file name of each picture be visible in the grid view?

-- Is there a finer grain way of rating photos besides 'favorites'?

-- Is there any way within Photos to access Photoshop or Photoshop Elements for more sophisticated editing?

Thanks.

Ed in Brooklyn