It's hard to give a straightforward yes or no. Comic Concepts has its pros and cons. Some of their products are great, but there have been issues with delivery and customer support in some cases.
It depends on a few factors. If the animation follows the original story closely, uses good quality graphics, and has a coherent plot, it could be considered legit. But if it strays too far or has poor production values, it might not be.
Well, the legitimacy of G Mart Comics is a bit of a mixed bag. Some customers swear by it, but others have run into various troubles when dealing with them.
Honestly, I don't know. You could look into its reputation in the manga community, or maybe see if there are any reports of scams or issues associated with it to determine if it's a trustworthy store.
One key element is skill. If you're a freelancer, say a programmer, being highly skilled in multiple programming languages will attract more clients. Another is reliability. Meeting deadlines and being available when clients need you. For example, a freelance graphic designer who always delivers on time. Also, marketing oneself. A freelance writer who promotes her work on social media is more likely to get noticed.
One common element is a strong skill set. Freelancers need to be really good at what they do. For example, a successful freelance photographer has to have great technical skills in using the camera and editing software.