This is accurate at big companies, but I think too much time doing other work and too little time doing core technical work is a sign of immature leadership. Joel Spolsky wrote in one of his blogs that a manager's job is to move obstacles out of the way so that employees can get stuff done. I think generally the longer you can keep your developers coding, the better off you will be.

Matches my experience. Unless you're working on cutting edge stuff chances are they you aren't writing anything _that_ complicated - and that the tricky bit of your job is understanding the requirements, not working out what combination of if statements/objects/functions is most useful for writing something that fulfils them.