1) I didn't specialize in any stack. I'm equally good across the board, but much slower. I can jump in and work at the senior/architect level in anything, but it takes me longer. I tend to do the architecture then pinch hit - if I'm working with a CCIE, I'll do the storage or server admin side. If I'm working with an RHCE, I'll do the network.

2) The more you understand networking, the better. Seriously. I can't tell you how many sysadmins I come across who have trouble understanding single-hop routing and some of the convolutions I've had to pull out of production environments because of it. The more you get networking, the more you'll be worth as a sysadmin. Even if you don't actually do the networking, the network team you work with will greatly appreciate you not immediately blaming them for every problem and actually helping to troubleshoot.

3) Less afraid than ever. This whole cloud thing has me laughing, because it's sort of like the "MY JOBS ARE GOING OVERSEAS" argument. No, the jobs aren't going overseas. They're going away. Automation is killing off the entire market for low-level-senior IT jobs; people who spent 30 years learning through osmosis and have no idea how to pick up new skills in a timely manner. I have standing job offers for both enterprise and big hosting companies if what I'm ever doing now crashes. Very few of these people are on Reddit, though, so I don't feel bad saying it here.