What kind of roof do you have? Most in that area are flat, but there are some with slate up front.
It's true, on the pick up thing you mentioned.
A flat roof is an inherently bad design, and as such warranted that way. Read any contract, including mine, and they will warranty it for about 10-12 years,
IF you have a service contract of silver coating it every 3 years. And in reality, roofs rarely ever fail, I've never had a call back for the roof. What fails is the seams. i.e. the flashing around the chimney, parapets connecting the two homes, sky lights etc...
Oh, and the number one reason roofs fail.........
Dish Network (or anything on your roof). I get calls for a leak and find that the home owner uses cable instead of dish and sold the dish to someone who just unscrewed the dish from the roof

. Never let anyone put a hole in your roof!!! Have it mounted on plywood and put two cinder blocks on it to keep it from moving.
Do a search on the BBB site to see if your contractor has any issues.
http://dc-easternpa.bbb.org/ That's a great free resource. If they are listed there in a
negative fashion, it usually is a bad sign. Reason is they want the two parties to first try to work it out. Only after will they be listed as a negative. And of course, ask for references.