While it is possible to have a problem with people/wildlife, I've never had a problem. If you use the ACA maps they tend to keep you off the high traffic roads so that conflicts with drivers in a hurry tend to be avoided. They also have a good "list" of campsites.
Pacing has never been a problem. Just ride at a pace that you are comfortable doing. When you tire - stop. Stop (take breaks) during the ride to enjoy the scenery or road side attractions. It breaks up the days ride and makes the trip more memorable. This way the terrain/wind becomes less an obstacle and more a chance to experience a different part of the country. You'll most likely find that some days you do more miles than planned and on other days you do fewer. Pretty soon you'll see that you develop an average and that may help you plan your route.
Wind for days on end can be discouraging but I've rarely found it to be a problem for more than a couple of days at a time.
Getting sick is always a concern but I carry my insurance card just in case. Never had to use it. I buy packaged food and get water at municipal faucets or bottled water at convenience stores. I also carry a cell phone. It may not work everywhere but it does work along about 90 plus percent of the routes I take. When there is coverage I check in with loved ones to reassure them that everything is ok.
On my first trip I packed too many changes of clothing. I've found that I only need three days of clothing changes (that includes the ones I'm wearing). I wash that days riding gear at night and let it dry overnight. On a rare occasion it may not be dry the next morning so the extra days stuff allows for an additional day to dry so I don't have to put on damp clothing and worry about saddle sores. Some will only carry two days and I met one person who only had 1 days worth. I prefer to wear "mountain bike" shorts over the "racing" style of shorts. I can wear them around as casual clothes after the ride and they have pockets to carry money. They also have a liner and pad to make the journey more comfortable.
Just remember that the only "hard" day was yesterday.