My single best piece of advice is to listen to and consider others advice but do what you think is best for YOU. In other words do what makes you smile.
If you want to carry that 10" cast iron skillet because you don't mind the weight and really enjoy the durability and heat distribution, then carry it regardless if others think you are nuts for carrying something that heavy. If you want to leave camp at 5am or 1pm, that is fine. If you want to stop early for the day or keep riding, do it (just be safe). This is your tour, not anyone else's. As you tour, you will quickly decide what works best for you.
That said, other advice I would suggest is to:
* Plan your route to where you connect to the TA. The area west of Purcellville can be a bit hectic with cars if you are not careful. You should try getting onto the Skyline Drive (no commercial vehicles and a reduced speed limit) at Front Royal or west of Sperryville.
* Have a few extra days buffer (at least 3) so you are not scrambling at the end to make Seattle. One day for boxing the bike (call ahead to bike shops to get one about a week out) and at least two in case you are held up due to weather, sickness, mechanical, etc. in the last few weeks. Worst case is you arrive early and can do a quick tour of the San Juan Islands (mostly vehicle free small islands accessible via ferry) near Seattle.
* I was going to say don't book a non-changeable return date as the pressure to finish on X day can make you miss some wonderful parts of the tour.
* Don't worry about the weather, etc. You will get wet, hot, and cold. But overall the days will be nice.
* Don't worry about getting shot, robbed, etc. Outside of major cities, the USA is pretty friendly and helpful, especially to Europeans (you're exotic).
* The saying "Don't talk politics, religion, or whiskey" has a pretty big grain of truth to it though this rarely comes up on its own.* Since you are westbound, avoid riding into the setting sun as cars may have a difficult time seeing you.* Know that "stealth camping" on private land can be frowned upon though the ACA maps are pretty good about showing where camping is available. A website like iOverlander or Outly allow you to see lots of legal dispersed camping in the western United States.
* Plan ahead a bit in the west in that it is not uncommon for places to be closed on Sunday. Always carry a spare emergency "meal" though I always have peanut butter and flour tortillas with me.
* America is a big country. Know you WILL have some crappy days in scenery, weather, etc. Just know that those crappy days are not the norm.* Most of all, enjoy the tour.
Hope you have a wonderful holiday! Tailwinds, John