Q1. They clean the inside of the case of any loose powder but no they don't clean the inside to be shiny and new looking like the outside. Unless your shooting one of the blackpowder cartridges, its not really needed.
Cleaning cases isn't really necessary. The main reasons to clean them are to inspect for cracks, keep grit out of your dies for longer die life and for looks. When I'm working up loads for a rifle/handgun, I use a set number of cases and only clean the necks/shoulder with steel wool and brush the insides of the necks to keep my dies clean. After I establish my loads, all cases are cleaned in a tumbler before loading for easier case inspection.
For a regular tumbler, I like the Dillon and Vibrashine. The midway model works ok but I have had to send them in for repair. With midway selling out and no longer having the lifetime warranty, I don't care for their model much anymore.
Probably the best for super spotless cases would be a rotating cleaner like the RCBS with there liquid cleaner/water mix.
On another note, if you get a standard tumbler case cleaner always use the lid. Tumbling without the lid can release lead into the air according to the NRMA.