Is it possible to cause premature wear to your motorcycle’s clutch by keeping it engaged too long?
Do I need to drop into neutral each time I am at a standstill?

Not necessarily. If your clutch cable is adjusted correctly and disengages when the lever is depressed, then there is no harm whatsoever. However, a poorly adjusted clutch or a loose grip on the clutch lever could see the clutch plates slipping and generating heat and wear.
Should I hold the clutch while turning the motorcycle?
You should use the clutch when turning on a motorcycle. Without the clutch, you are freewheeling, which means you have no control over the motorcycle.
You need clutch control when turning a motorcycle at low speed. To turn successfully, you will constantly add and reduce clutch inputs to maintain speed and control.
Because you are turning at low speed, you can use the clutch lever for speed control while keeping a steady rev range, less to think about and coordinate in a manoeuvre.
Is it bad to feather the clutch on a motorcycle?
It depends. In terms of the longevity of the clutch, then it’s undoubtedly going to wear quicker, but there are advantages to feathering your clutch.
Motorcycle engines develop their power at the higher end of the rev range. Now, if you are riding along at 30mph, how will you accelerate quickly? Feather the clutch?
Feathering the clutch for a second allows you to quickly get to the rev range in the power band to accelerate quickly. Be careful not to flip the motorcycle if you snap the clutch out.
Obviously, this practice allows the clutch plates to slip and build up heat which contributes to wear and failure.
So is it bad for your motorcycle clutch? You could say yes, but it’s good for getting you moving faster.
Is it bad to not use the clutch on a motorcycle?
No, it’s not bad if done correctly. Most motorcyclists use the clutch. That’s what it’s there for. But, you can clutchless shift, which is precisely what it sounds like. You don’t use the clutch lever.
You can’t select 1st clutchless shifting. If you are rolling, it’s a case of matching the motorcycle’s ground speed and engine revs, then upshifting. This will not hurt the transmission in any way.
Downshifting is a little more complicated, but with practice can be done.
Does holding a clutch save fuel in a bike?
No, nothing significant. Coasting makes you lose control of your bike. You cannot wind on the power quickly and may find yourself in the wrong gear.
Coasting can mean using the brakes more and not using engine braking that will prematurely wear your brake pads. Also, if your pads are hot, you may experience brake fade, reducing braking efficiency.
If you need to let your clutch out suddenly, you could end up in a slide or swerve that you can not control. Don’t try to save fuel by coasting.