I'm a former heroin addict (9 years clean in August) but I also have severe fibro and can't even stand that long. I'm also job hunting after losing my last job because I went to the hospital (for psych reasons) and had to call off a whole week of work. I've read up and it seems like what I should get is red vein but I have no experience with kratom.
I take it on weekends and have quit drinking because of it. I usually stick to 2.5-3 grams once or twice a day. At this rate of usage i go through about 40 dollars worth every three months.
All the different names are just marketing. Red kratom is supposedly processed differently which converts some of the active ingredients into being more pain relieving and sedating, but I can't tell much difference.
Generally, from what I've seen, people who have the most problems with it tend to view it as benign and take it all the time as part of pain management, or they keep upping the dosage (like 20 grams a day or more) chasing the euphoric feeling you can get, and then try to quit and have withdrawals similar to other opiates.
I've also heard of people with previous opiate addictions getting physically addicted to it and having problems quitting. It hits part of the same receptors that opiods hit, so it's something to be careful with, but it's much harder to overdose the way you can with straight up opiates.
AFAIK there hasn't been a death related to kratom where it wasn't part of a cocktail of other serious drugs in someone's system. I'm sure it's possible, but it generally makes you sick if you try to take too much.