You seem to have desire but little to no experience. I'd suggest gathering your gear and taking an overnight ride somewhere just to check out your set up. This will answer some of your questions and present others. The only way to get experience is to do some local bike touring.

For the most part, I find bike touring in the UK to be a lot of up and down but services at a reasonable distance. Keep off the A roads. Seek out the country lanes.

In 2011, I rode much of the way from Land's End in England to Fort William in Scotland. It was a fabulous ride, but I spent far more than £5 a day. You can read my journal of that ride, if your looking for a place to start.

Your specific questions.

1. I used the AAA 3 miles to the inch road atlas and then use your smart phone or local maps for larger towns as the AAA atlas isn't good in the bigger towns.

2. Pack your gear in the rear panniers (is this a trick question?). Or, only take as much gear as you can put in the panniers. This is possible if you don't camp or cook.

3. Eating on tour is something I like to enjoy. Scrimp here if you must but be sure to eat enough food.

4. Use hospitality websites like couchsurfing.org or warmshowers.org and take a shower there.

5. Read journals at crazyguyonabike.com, check out this LEJOG forum: http://www.cyclechat.net/forums/land...roats-lejog.9/ , read the CTC touring forum: http://forum.ctc.org.uk/viewforum.php?f=16 .