If you have the coding skills sufficient to work in the outside world, then you probably don't need to further significantly strengthen those skills in order to work from home. What you do need to work from home is the appropriate physical space (i.e. an office that you can secure), high-speed internet capability, the ability to prioritize, self-motivation and the ability to work autonomously. Those last few are personality traits....and probably can't be learned, so if you don't already have that kind of personality, be cautious about what you're signing up for. There's a lot of misconception about working from home.....you can't always make your own hours, you can't always work in your jammies, and you can't always have 15 hours to do 8 hours of work while you shuffle laundry and feed the kids inbetween. I have home coders and they have set hours, they have to be ready to come into the office if they're needed here, and they have to work productively during the day. Plus they miss out on the birthday celebrations, the impromptu workplace meetings and the comraderie of an office situation.
Although I understand your frustration with your old fashioned providers, there isn't a job out there that doesn't have issues. A commute to a bigger city might be a better choice than a work-from-home situation that leaves you bored, lonely and uninspired, and treated like a robot.
If you do decide to look into this company, ask for references---real ones from actual employees or clients who aren't being paid to advertise. Google the company and find out who they really are. Don't be dazzled by a flashy presentation and a promise of a lucrative career. As a coder, you already have the skills, so make sure they don't take advantage of your dissatisfaction at your current job.
Let's look at this in another way....what have you done to improve your current situation? There's a difference between doing it 'the old fashioned way', and doing it the non-compliant way. If they're still having you type HCFAs, you might put together a business proposal that walks them through the process of an affordable electronic health record initiation...and then point out the financial benefits of Meaningful Use. Have they any idea about ICD-10? Provide them with the education, the steps and the risk if they're not on board in time. Sometimes people are afraid to change because they don't have the details or the know-how. If they're asking you to do things that are fraudulent, then you need to show them the regulatory guidance, and ask them to trust you (as a certified coder) to do the right things on their behalf. If they still balk, then it's time for a change.
If it sounds too good to be true, it probably is. This board is full of would-be coders who bought into those 'We'll teach you how to code and make 40K per year" schemes. You really have to make a decision that is right for you. None of us can tell you what to do, but we can ask you to make sure you do your research in advance (like all good coders should) before making a move.