Your salary should be adequate with all the things that are covered by the employer.
I have never tried to send money out of Ghana but as a lot of expatriates work here I am sure it must be possible.
If your work is providing medical cover they will be linked with a particular clinic and I am sure that they will have one of reasonable quality.
Ghana is a relatively safe country so security is not a big issue.
You will need a yellow fever certificate or you won't get into the country. I would also suggest you look on a travel website and look at the other vaccinations you need like Hep A and Hep B, typhoid, cholera, encephalytis, polio, TB, tetanus, rabies. These are all the ones I had when I came to Ghana in the 90s and have kept most of them up-to-date. Of course one of the main problems is malaria and you need to bring medication for that. Getting the treatment here though is often cheaper here than overseas.
Good luck with the move and I am sure you will enjoy your stay.