Professors don't care how many schools you. They just write one letter of recommendation and that is used for all schools. With CSDCAS this centralizes things so one letter can be sent to a central location and be used for several schools. You should also check if you school has a place where professors can deposit there letters and you can select which letters to send and to what schools. Even if you don't have one the biggest problem a professor would have with multiple schools is if you are not prepared. If they need to mail out letters through post you should be sure to supply them with envelopes that have postage and the appropriate address. If you have this it is only a matter of them putting letters in an envelope and mailing them out. I applied to 7 schools and it was not a problem for any of my professors because they had all the necessary documents. If a professor does have some absurd rule about a number that is where knowing professors comes into play because they may forgo that silly rule.
As for the question about the schools I can give you some help. I applied to both UNC and Maryland. I interviewed at UNC and was admitted and given aid to Maryland. UNC has some really nice facilities, lots of placement options, and is in a very nice area. However there is one big caveat that would make me advise you not to apply to UNC. The caveat is that they are in the medical college so there are no assistanships. The best they can do is give you some money from some pediatric grants they have but the biggest one was only 12,500 per year and if you are coming from out of state that does not even cover tuition. So while it is a great program unless you are well off or don't mind a great deal of debt I would strongly advise you against applying to UNC.
I have only good things to say about Maryland. They have a very large audiology staff that covers a wide range of specialties. The campus is great, lots to do in the surrounding area. Placements are great as it is located right near DC and numerous other large cities on the eastern seaboard. They also have assistanships both inside and outside the department to help both in state and out of state students. I would strongly recommend you apply to Maryland. I can give you more specifics too just post them or send me a message, posting may be better so that others can see.
On a final note instead of applying to UNC I would recommend you apply to James Madison University. Everyone attending has an assistanship, which is great anyway you cut it. They have a great staff that are very nice and welcoming. They are a little off the road but they make up for it in the excellence of their facilities and their great professors. So forget applying to UNC applying to James Madison, you will be much happier for it. Let me know if you have more questions about these schools or about grad school. Hope this helped to answer some questions.
