Hi Andy
A lot of people get into carpet cleaning - some succeed and some fail.
There are two fundamental points I'd make:
You've clearly taken some time to help yourself by going through the the old posts looking for valuable information before asking your question. As they say, success is where hard work meets opportunity and I applaud you for taking the time to look into it in such detail.
Secondly, you actually have a plan and if you stick to it you will have a better chance than most of making it work. However, bear in mind that it is hard work and it is likely to take some time to establish a reasonable living!
Don't get too sidetracked by the different training courses available. The important thing is that you're prepared to invest in it in the first place. Personally, I don't think a single course is enough, and, if you're committed to offering a professional range of services, you're likely to have to do several anyway. All the courses mentioned are good and will give you a good start.
Good luck with it.
Mike Boxall