Is having a malocclusion (nonperfect bite) a huge problem if tmd?

Probably, yes. A significant malocclusion, or bad bite, is a risk factor for the development of tmd, and will certainly exacerbate an existing TMJ problem. This may be corrected temporarily by splint therapy, but a permanent solution will require at least orthodontic treatment, and possibly orthognathic (reconstructive jaw) surgery. It depends, of course, on the magnitude of the malocclusion plus other factors.
Depends. A malocclusion can be a huge problem if you have tmj/tmd but it may not be the only contributing cause. Many people with severe malocclusion have no tmj/tmd. Need to see an orthodontist.
Depends. Up until about 10 years ago many dentist including myself, thought a malocclusion was related to tmd. Since then there is more and more research indicating it has at best a minor role in most cases. Because it has been so ingrained into our teaching as dentists you may see different opinions. Treatment that involves TMJ surgery or extensive dental care to correct the bite is rare in my practice.
Not nessarily. Most malocclusions are not associated with TMD. Some patients with perfect bites have TMD. The bite has to be addressed, but should not prevent a good result.
Yes. In my experience when we correct malocclusion tmd symptoms diminish or disappear 90% of the time, 7% are unchanged, and 3% actually get worse.