Why are you so fixated on the Hs.app anyways? That step is completely irrelevant if you already have FBI. However it's worth noting that if you've deleted your actual health and safety from your console, and you want it back, then perform a system update on the console. This will fix Health and Safety. You don't really need it though but you might as well.
And yes you're ready, but I'd still put the arm9loaderhax.bin file on the CTR NAND so you can boot without SD card if need be .. That's why I'm rather puzzled when you say you can't access it. Are you following the instructions word to word?
And I must ask is the reason you weren't able to install anything on the SD card previously because you tested your Sd card with h2testw but didn't remove the test files? Those files test the SD card by writing on it and your SD card was effectively full if you didn't remove them -_-.
Also make damn sure you have your NAND backup and that you copy it to multiple places juuust in case.