I think it's unrealistic to think that all funds donated go directly into food etc for the people that need it. At the end of the day the donations are given to buy services and products, that is everything from services that directly help the target group, such as transport and food items, to the living expenses of volunteers working in the field to the costs of raising the money in the first place.
I make a point of not giving to charities that ask me via tele-sales, I then know that the first bite of the cherry goes to the person calling me. I priorities people with a collection tin in their hands as I know that it's pretty much always voluntary. I also prioritise people actually doing something for the money rather than just asking for handouts, I feel it's showing some sort of appreciation for the money given, for example, I just ordered a huge bag of kitchen paper from my local ice-hockey club. It's not raising money for the pros but for the youth teams so that they have enough equipment. My local ice hockey team is not big enough for the sponsorship deals that pay for everything, including the kids and I like to thing it's helping the local society, giving kids another option.
All this said, I think that when services can be got from volunteers then they should be, of course all charities have to pay for accountants and the like but traditionally people are willing to give their time (much more precious than money) for a good cause and in my opinion this should be encouraged and this is a great way to actually raise the funds.
Regards the top men/women, it's a difficult question as morally no one should get rich from charity donations. On the other hand, to get the top people you have to pay top money and if employing the top person means that more money is raised and the money raised is used more efficiently then the cost of their wages should be more than offset by the benefits of employing them. The litmus test has to be, does has the charity managed to help more people as a result of the person's employment? If the answer is yes then it is a bitter pill that should be swallowed with a smile on our faces but of not then they should be replaced with someone who will do the job for less.