Could be your programming, could be your form, or it could just be your proportions. Look at DirtyRed, he can squat a truck, but he hasn't had near the same success in bench or deadlift. It's largely based on how he's built.
Not without knowing more about what you've been doing.
Not necessarily. The top competitors at his height might be around there, but that doesn't mean that's where he's most competitive. If he can only get up to, say, 97.5 kg/215 lbs before any additional weight is 90% fat, then he's probably most competitive as a 93 kg or 105 kg lifter. That's not to say he'll be his strongest there, but he'd probably have his highest Wilks. Though even hitting your highest Wilks score doesn't necessarily mean you'll be your most competitive, since it depends how strong the competitors who show up may be.
For example, the best strongman at my height is Eddie Hall at 410 lbs. If I were 410 lbs, I would be a tub of lard, and probably not noticeably stronger than I'd be at 350.
none of this is to say he should stay at the weight he's at, whether to maximize his competitive advantage or for other reasons, just that he personally may not be most competitive at 240 lbs. But then again, he may. Hard to say without even seeing him.
It's not, really. The guy who weighs 100 kg might be the heaviest guy there, but the term "super heavyweight" specifically refers to the top, unlimited weight class, and only in certain sports. The ones I know that use the term are powerlifting (+120/+140), Olympic lifting (+105), and MMA (+120). Boxing and Judo have unlimited classes at 100 kg, but that class is referred to as "heavyweight" in those sports. So, I might be missing one, but I don't know of a weight class sport that actually refers to someone over 100 kg as a super heavyweight.
1)True-ish. 2) Dependent on 1, so true-ish. 3) False. 4) Dependent on 3, so also false.
Most guys in drug tested sports will not be below 10%. There are exceptions, obviously, but it's not the norm, especially for guys over ~90kg.
You could do a DEXA scan if you're like. But how much muscle your frame can hold is more about your bone structure/size, rather than bone density. Not that bone density doesn't matter, but that will change with training, unlike your overall bone structure.