Yes you are right on the list of equipment needed. You will need deep cycle battery(expensive), Solar charge controller(depends on features, could be expensive), sufficient solar panels, and Inverter if you need AC.

1) Lots of factor, those panels rarely operates and maximum efficiency due to many factor. Also must take into account losses etc.

2) 100W, assuming 12V system, will draw about 8amps. Let's say you are using 60amp/hour battery, and the battery is deep cycle marine type. You could only run it down to about 30% of full capacity, so thats about 42amp/hour. thats leave you 6 hours of operation. But in my experience you should get much less due to voltage drop and your equipment cant function properly.

ya. in real theory yes. but there is problems.
1. voltage drop
2. battery discharge cycle (you can't run down battery until 0%, will spoil very fast. car battery cannot discharge more than 80%)

if you got any 'cable' working in telekom, you might be able to score some deep discharge type battery. very big and heavy.