1- I looked into this kind of emergency power source, but found carrying a extra battery a cheaper and easier solution for me. A 2200mah battery can be found on ebay for $15 or so. Because of it's added bulk (adds ~ 1/4" to the Ax thickness), I use the standard 1100mah battery for day to day and carry the larger battery in my briefcase as a backup. There are plans floating around this forum on how to build one of those chargers for under $10.
2- Doesn't look too different from the
Arkon mounts. It seems a bit expensive to me, but if you're unsure of which attachment will work best, this may be a good choice. I've successfully used Arkon vent mounts for years.
3- I use the high current charger/minisync combo all the time with no flickering back light issue. Depending on the car power plug, If the Ax's battery is depleted beyond 20%-40%, you might not be able to use and charge at the same time.
__________________
012009
Sharp Zaurus 5000 > Sharp Zaurus 5800 > Casio E-100 > Casio E-115 > Dell Axim X-5 (forever lost

) > Toshiba e805(Wifes "new" PDA) > Dell Axim X51v >+ Verizon xv6700