Welcome aboard the RoadTrip America Forums!

Since you've already done some travelling in the US, you do seem to have an appreciation for its size at least, but several other of your questions indicate that you need to start thinking of it as a continent rather than a country. Climates vary from desert to sub-tropical to arctic. Wildlife abounds everywhere, but there is certainly no short list of 'bugs' to worry about. Yes there are chiggers in the southeast, black flies in the north east, mosquitoes almost anywhere you find standing water, but there are also snakes, bears, javelina, moose, mountain lions, scorpions, etc. This is not meant to scare you off at all. People drive and camp all over this continent every day of the year. It's just that your questions don't have simple answers.

Then, too, it's not going to be that simple for you, as a foreigner, to buy, license register, and insure a bike here. These discussions will help get you started, but your longest road may be the one through the red tape. The one type of insurance that you must have is liability, coverage for any damage or injury you may cause to someone else. How much of that you need will vary by state, with the state you register the bike in having jurisdiction. How much coverage you have on yourself and the bike (comprehensive) is up to you. Same with your kit. SatNav will work, but you'll probably have to pay to get the data on American roads. A good paper atlas would be a whole lot cheaper, give you a good synoptic view, and becomes a good souvenir.

Route and time of year: For a 6 month trip, I'd suggest landing in Florida (if that's what works for you) in Spring (say May) work your way up the east coast and Appalachian Mountains to the Great Lakes, take the summer to cross the northern plains and Rockies to the Pacific Northwest, come down along the coast as fall sets in, and enjoy the desert as late in the fall as you can. You don't want to be here in the summer! In Tucson today (June 20) we hit 110°F (43°C), and it's only going to get hotter.That should answer your basic questions and give you a bit to mull on for a while!

AZBuck