Another DaisyDisk recommendation here, the UI is very fast to drill down into the directory structure and add stuff to a collector to delete in one go.
Absolutely. No need to pay for something when the free version is better. Note that if you run either of these as sudo (so you can see other users files) and delete then things will end up in root's trash can which can be even more annoying.
If you only have one user either is fine. There are also various Java based scanners which are similar.
Another DaisyDisk recommendation here, the UI is very fast to drill down into the directory structure and add stuff to a collector to delete in one go.