Congrats on the new camera and happy belated b-day!

I'm in agreement with brewercm, cheap filters can degrade image quality and the way I look at it is if you're making a serious investment in a nice camera you should either use a good filter or none at all under normal conditions. If you're going to be someplace where you truly need protection you can always attach a cheap filter for protection. For the record I don't use filters for protection purposes but I understand and accept the risk in not doing so.

Re: lens size, it really is a big change if you're used to point and shoots but I'm sure you'll appreciate the fast response time and excellent quality once you get comfortable with the gear.