iTunes stop/start play of songs + no longer can access iTunes Store - Any known fixes?

I have an iMac. It is running Snow Leopard 10.6.8. My iTunes is 11.1.5.

All of a sudden today, iTunes started three odd and frustrating behaviors:

1) While songs are playing, it randomly starts and stops them - no rhym or reason that I can tell.

2) Simultaneously, I now cannot connect to the iTunes Store. More accurately, when I click on the iTunes Store icon it takes me to what appears to be the store loading...but then it just stalls there and ends up with a blank white page. The top part of the strore nav is there, but where you would normally see all the albums, songs, movies, etc., etc. is just a blank white page.

3) It seems that while iTunes is open, it now slows down every other application on my iMac - disrupting and delaying use of Safari, Firefox and other applications. When all other applications are off, iTunes continues to do #1 and #2 above. And, when iTunes is off...other applications run OK. So, it seems to be iTunes that is the problem.

I've looked around on these forums and while there are some similar issues discussed, I can't seem to find a fix or advice on what might be the issue and perhaps how to fix it.

I appreciate any insight people might have.