Just in case you’re not aware: the Fn key, in conjunction with the arrow keys or the delete key, let you type those keys. Though that’s certainly not as convenient as having dedicated keys.
Also, you can remap different keys to those keys with the free software KeyRemap4MacBook (https://pqrs.org/macosx/keyremap4macbook/index.html.en). For instance, you can remap \ to be forward-delete and Fn+\ to be typing ‘\’.
That's fine and good, until you want to use key combinations that include the missing keys, particularly selection type stuff. For me, it comes up a lot in programming, writing, and file/photo management.
Also, you can remap different keys to those keys with the free software KeyRemap4MacBook (https://pqrs.org/macosx/keyremap4macbook/index.html.en). For instance, you can remap \ to be forward-delete and Fn+\ to be typing ‘\’.