va, all good questions.
1. Potato works great. You can also buy some inexpensive stove temp gauges at most hardward stores that work fine. ($4-5 range) Maverick makes a nice one for about $15.
2. Bottom does not real real hot because the charcoal basket should be about 3" from the bottom. That allows the ash to collect under the fire and airflow under the fuel to burn properly.
3. Fuel is your choice. Any combination will work. If you have a preference, use that and put a 2-4 wood chunks in for flavor. That is all the wood you really need even in a 10-12 hour burn with about 1--12 lbs of fuel. I mix about half and half with lump and charcoal, and I know it will be consistant. That just comes from practice.
Hope this helps and good luck with the build. You will not be sorry!!!!!!!!!!!
my avatar swiped fatties from the plate....look how sorry he is.
NB Bandera with mods
Weber 22 .5" x 2, 26.75" x 1
UDS x 3
Created "The Great Spam Revelation of 2011."